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1152 lines
36 KiB
C
1152 lines
36 KiB
C
/*
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parse: spawned from common; clustering around stream/frame parsing
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copyright ?-2009 by the mpg123 project - free software under the terms of the LGPL 2.1
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see COPYING and AUTHORS files in distribution or http://mpg123.org
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initially written by Michael Hipp & Thomas Orgis
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*/
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#include "mpg123lib_intern.h"
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#include <sys/stat.h>
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#include <fcntl.h>
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#include "getbits.h"
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#if defined (WANT_WIN32_SOCKETS)
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#include <winsock2.h>
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#include <ws2tcpip.h>
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#endif
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/* a limit for number of frames in a track; beyond that unsigned long may not be enough to hold byte addresses */
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#ifdef HAVE_LIMITS_H
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#include <limits.h>
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#endif
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#ifndef ULONG_MAX
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/* hm, is this portable across preprocessors? */
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#define ULONG_MAX ((unsigned long)-1)
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#endif
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#define TRACK_MAX_FRAMES ULONG_MAX/4/1152
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#include "debug.h"
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#define bsbufid(fr) (fr)->bsbuf==(fr)->bsspace[0] ? 0 : ((fr)->bsbuf==fr->bsspace[1] ? 1 : ( (fr)->bsbuf==(fr)->bsspace[0]+512 ? 2 : ((fr)->bsbuf==fr->bsspace[1]+512 ? 3 : -1) ) )
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/*
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AAAAAAAA AAABBCCD EEEEFFGH IIJJKLMM
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A: sync
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B: mpeg version
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C: layer
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D: CRC
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E: bitrate
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F:sampling rate
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G: padding
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H: private
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I: channel mode
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J: mode ext
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K: copyright
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L: original
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M: emphasis
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old compare mask 0xfffffd00:
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11111111 11111111 11111101 00000000
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means: everything must match excluding padding and channel mode, ext mode, ...
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But a vbr stream's headers will differ in bitrate!
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We are already strict in allowing only frames of same type in stream, we should at least watch out for VBR while being strict.
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So a better mask is:
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11111111 11111111 00001101 00000000
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Even more, I'll allow varying crc bit.
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11111111 11111110 00001101 00000000
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(still unsure about this private bit)
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*/
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#define HDRCMPMASK 0xfffe0d00
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#define HDRSAMPMASK 0xc00 /* 1100 00000000, FF bits (sample rate) */
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/* bitrates for [mpeg1/2][layer] */
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static const int tabsel_123[2][3][16] =
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{
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{
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{0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,},
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{0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,},
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{0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,}
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},
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{
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{0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,},
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{0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,},
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{0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,}
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}
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};
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const long freqs[9] = { 44100, 48000, 32000, 22050, 24000, 16000 , 11025 , 12000 , 8000 };
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static int decode_header(mpg123_handle *fr,unsigned long newhead);
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/* These two are to be replaced by one function that gives all the frame parameters (for outsiders).*/
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int frame_bitrate(mpg123_handle *fr)
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{
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return tabsel_123[fr->lsf][fr->lay-1][fr->bitrate_index];
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}
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long frame_freq(mpg123_handle *fr)
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{
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return freqs[fr->sampling_frequency];
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}
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#define free_format_header(head) ( ((head & 0xffe00000) == 0xffe00000) && ((head>>17)&3) && (((head>>12)&0xf) == 0x0) && (((head>>10)&0x3) != 0x3 ))
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/* compiler is smart enought to inline this one or should I really do it as macro...? */
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int head_check(unsigned long head)
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{
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if
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(
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/* first 11 bits are set to 1 for frame sync */
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((head & 0xffe00000) != 0xffe00000)
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||
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/* layer: 01,10,11 is 1,2,3; 00 is reserved */
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(!((head>>17)&3))
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||
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/* 1111 means bad bitrate */
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(((head>>12)&0xf) == 0xf)
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||
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/* sampling freq: 11 is reserved */
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(((head>>10)&0x3) == 0x3 )
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/* here used to be a mpeg 2.5 check... re-enabled 2.5 decoding due to lack of evidence that it is really not good */
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)
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{
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return FALSE;
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}
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/* if no check failed, the header is valid (hopefully)*/
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else
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{
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return TRUE;
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}
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}
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static int check_lame_tag(mpg123_handle *fr)
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{
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/*
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going to look for Xing or Info at some position after the header
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MPEG 1 MPEG 2/2.5 (LSF)
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Stereo, Joint Stereo, Dual Channel 32 17
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Mono 17 9
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Also, how to avoid false positives? I guess I should interpret more of the header to rule that out(?).
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I hope that ensuring all zeros until tag start is enough.
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*/
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int lame_offset = (fr->stereo == 2) ? (fr->lsf ? 17 : 32 ) : (fr->lsf ? 9 : 17);
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/* At least skip the decoder delay. */
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#ifdef GAPLESS
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if(fr->p.flags & MPG123_GAPLESS)
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{
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if(fr->begin_s == 0) frame_gapless_init(fr, GAPLESS_DELAY, 0);
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}
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#endif
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if(fr->framesize >= 120+lame_offset) /* traditional Xing header is 120 bytes */
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{
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int i;
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int lame_type = 0;
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debug("do we have lame tag?");
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/* only search for tag when all zero before it (apart from checksum) */
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for(i=2; i < lame_offset; ++i) if(fr->bsbuf[i] != 0) break;
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if(i == lame_offset)
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{
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debug("possibly...");
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if
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(
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(fr->bsbuf[lame_offset] == 'I')
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&& (fr->bsbuf[lame_offset+1] == 'n')
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&& (fr->bsbuf[lame_offset+2] == 'f')
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&& (fr->bsbuf[lame_offset+3] == 'o')
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)
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{
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lame_type = 1; /* We still have to see what there is */
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}
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else if
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(
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(fr->bsbuf[lame_offset] == 'X')
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&& (fr->bsbuf[lame_offset+1] == 'i')
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&& (fr->bsbuf[lame_offset+2] == 'n')
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&& (fr->bsbuf[lame_offset+3] == 'g')
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)
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{
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lame_type = 2;
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fr->vbr = MPG123_VBR; /* Xing header means always VBR */
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}
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if(lame_type)
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{
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unsigned long xing_flags;
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/* we have one of these headers... */
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if(VERBOSE2) fprintf(stderr, "Note: Xing/Lame/Info header detected\n");
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/* now interpret the Xing part, I have 120 bytes total for sure */
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/* there are 4 bytes for flags, but only the last byte contains known ones */
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lame_offset += 4; /* now first byte after Xing/Name */
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/* 4 bytes dword for flags */
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#define make_long(a, o) ((((unsigned long) a[o]) << 24) | (((unsigned long) a[o+1]) << 16) | (((unsigned long) a[o+2]) << 8) | ((unsigned long) a[o+3]))
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/* 16 bit */
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#define make_short(a,o) ((((unsigned short) a[o]) << 8) | ((unsigned short) a[o+1]))
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xing_flags = make_long(fr->bsbuf, lame_offset);
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lame_offset += 4;
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debug1("Xing: flags 0x%08lx", xing_flags);
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if(xing_flags & 1) /* frames */
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{
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if(fr->p.flags & MPG123_IGNORE_STREAMLENGTH)
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{
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if(VERBOSE3)
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fprintf(stderr, "Note: Ignoring Xing frames because of MPG123_IGNORE_STREAMLENGTH\n");
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}
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else
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{
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/*
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In theory, one should use that value for skipping...
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When I know the exact number of samples I could simply count in flush_output,
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but that's problematic with seeking and such.
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I still miss the real solution for detecting the end.
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*/
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fr->track_frames = (off_t) make_long(fr->bsbuf, lame_offset);
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if(fr->track_frames > TRACK_MAX_FRAMES) fr->track_frames = 0; /* endless stream? */
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#ifdef GAPLESS
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/* if no further info there, remove/add at least the decoder delay */
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if(fr->p.flags & MPG123_GAPLESS)
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{
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off_t length = fr->track_frames * spf(fr);
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if(length > 1)
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frame_gapless_init(fr, GAPLESS_DELAY, length+GAPLESS_DELAY);
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}
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#endif
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if(VERBOSE3) fprintf(stderr, "Note: Xing: %lu frames\n", (long unsigned)fr->track_frames);
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}
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lame_offset += 4;
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}
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if(xing_flags & 0x2) /* bytes */
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{
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if(fr->p.flags & MPG123_IGNORE_STREAMLENGTH)
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{
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if(VERBOSE3)
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fprintf(stderr, "Note: Ignoring Xing bytes because of MPG123_IGNORE_STREAMLENGTH\n");
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}
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else
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{
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unsigned long xing_bytes = make_long(fr->bsbuf, lame_offset); /* We assume that this is the _total_ size of the file, including Xing frame ... and ID3 frames...
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It's not that clearly documented... */
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if(fr->rdat.filelen < 1)
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fr->rdat.filelen = (off_t) xing_bytes; /* One could start caring for overflow here. */
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else
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{
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if((off_t) xing_bytes != fr->rdat.filelen && NOQUIET)
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{
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double diff = 1.0/fr->rdat.filelen * (fr->rdat.filelen - (off_t)xing_bytes);
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if(diff < 0.) diff = -diff;
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if(VERBOSE3)
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fprintf(stderr, "Note: Xing stream size %lu differs by %f%% from determined/given file size!\n", xing_bytes, diff);
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if(diff > 1.)
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fprintf(stderr, "Warning: Xing stream size off by more than 1%%, fuzzy seeking may be even more fuzzy than by design!\n");
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}
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}
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if(VERBOSE3)
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fprintf(stderr, "Note: Xing: %lu bytes\n", (long unsigned)xing_bytes);
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}
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lame_offset += 4;
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}
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if(xing_flags & 0x4) /* TOC */
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{
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frame_fill_toc(fr, fr->bsbuf+lame_offset);
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lame_offset += 100; /* just skip */
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}
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if(xing_flags & 0x8) /* VBR quality */
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{
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if(VERBOSE3)
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{
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unsigned long xing_quality = make_long(fr->bsbuf, lame_offset);
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fprintf(stderr, "Note: Xing: quality = %lu\n", (long unsigned)xing_quality);
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}
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lame_offset += 4;
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}
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/* I guess that either 0 or LAME extra data follows */
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/* there may this crc16 be floating around... (?) */
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if(fr->bsbuf[lame_offset] != 0)
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{
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unsigned char lame_vbr;
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float replay_gain[2] = {0,0};
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float peak = 0;
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float gain_offset = 0; /* going to be +6 for old lame that used 83dB */
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char nb[10];
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memcpy(nb, fr->bsbuf+lame_offset, 9);
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nb[9] = 0;
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if(VERBOSE3) fprintf(stderr, "Note: Info: Encoder: %s\n", nb);
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if(!strncmp("LAME", nb, 4))
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{
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gain_offset = 6;
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debug("TODO: finish lame detetcion...");
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}
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lame_offset += 9;
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/* the 4 big bits are tag revision, the small bits vbr method */
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lame_vbr = fr->bsbuf[lame_offset] & 15;
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if(VERBOSE3)
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{
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fprintf(stderr, "Note: Info: rev %u\n", fr->bsbuf[lame_offset] >> 4);
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fprintf(stderr, "Note: Info: vbr mode %u\n", lame_vbr);
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}
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lame_offset += 1;
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switch(lame_vbr)
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{
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/* from rev1 proposal... not sure if all good in practice */
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case 1:
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case 8: fr->vbr = MPG123_CBR; break;
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case 2:
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case 9: fr->vbr = MPG123_ABR; break;
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default: fr->vbr = MPG123_VBR; /* 00==unknown is taken as VBR */
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}
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/* skipping: lowpass filter value */
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lame_offset += 1;
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/* replaygain */
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/* 32bit float: peak amplitude -- why did I parse it as int before??*/
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/* Ah, yes, lame seems to store it as int since some day in 2003; I've only seen zeros anyway until now, bah! */
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if
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(
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(fr->bsbuf[lame_offset] != 0)
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|| (fr->bsbuf[lame_offset+1] != 0)
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|| (fr->bsbuf[lame_offset+2] != 0)
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|| (fr->bsbuf[lame_offset+3] != 0)
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)
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{
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debug("Wow! Is there _really_ a non-zero peak value? Now is it stored as float or int - how should I know?");
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/* byte*peak_bytes = (byte*) &peak;
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... endianess ... just copy bytes to avoid floating point operation on unaligned memory?
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peak_bytes[0] = ...
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peak = *(float*) (fr->bsbuf+lame_offset); */
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}
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if(VERBOSE3) fprintf(stderr, "Note: Info: peak = %f (I won't use this)\n", peak);
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peak = 0; /* until better times arrived */
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lame_offset += 4;
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/*
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ReplayGain values - lame only writes radio mode gain...
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16bit gain, 3 bits name, 3 bits originator, sign (1=-, 0=+), dB value*10 in 9 bits (fixed point)
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ignore the setting if name or originator == 000!
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radio 0 0 1 0 1 1 1 0 0 1 1 1 1 1 0 1
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audiophile 0 1 0 0 1 0 0 0 0 0 0 1 0 1 0 0
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*/
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for(i =0; i < 2; ++i)
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{
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unsigned char origin = (fr->bsbuf[lame_offset] >> 2) & 0x7; /* the 3 bits after that... */
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if(origin != 0)
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{
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unsigned char gt = fr->bsbuf[lame_offset] >> 5; /* only first 3 bits */
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if(gt == 1) gt = 0; /* radio */
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else if(gt == 2) gt = 1; /* audiophile */
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else continue;
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/* get the 9 bits into a number, divide by 10, multiply sign... happy bit banging */
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replay_gain[0] = (float) ((fr->bsbuf[lame_offset] & 0x2) ? -0.1 : 0.1) * (make_short(fr->bsbuf, lame_offset) & 0x1f);
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}
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lame_offset += 2;
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}
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if(VERBOSE3)
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{
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fprintf(stderr, "Note: Info: Radio Gain = %03.1fdB\n", replay_gain[0]);
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fprintf(stderr, "Note: Info: Audiophile Gain = %03.1fdB\n", replay_gain[1]);
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}
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for(i=0; i < 2; ++i)
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{
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if(fr->rva.level[i] <= 0)
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{
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fr->rva.peak[i] = 0; /* at some time the parsed peak should be used */
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fr->rva.gain[i] = replay_gain[i];
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fr->rva.level[i] = 0;
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}
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}
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lame_offset += 1; /* skipping encoding flags byte */
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if(fr->vbr == MPG123_ABR)
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{
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fr->abr_rate = fr->bsbuf[lame_offset];
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if(VERBOSE3) fprintf(stderr, "Note: Info: ABR rate = %u\n", fr->abr_rate);
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}
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lame_offset += 1;
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/* encoder delay and padding, two 12 bit values... lame does write them from int ...*/
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if(VERBOSE3)
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fprintf(stderr, "Note: Encoder delay = %i; padding = %i\n",
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((((int) fr->bsbuf[lame_offset]) << 4) | (((int) fr->bsbuf[lame_offset+1]) >> 4)),
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(((((int) fr->bsbuf[lame_offset+1]) << 8) | (((int) fr->bsbuf[lame_offset+2]))) & 0xfff) );
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#ifdef GAPLESS
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if(fr->p.flags & MPG123_GAPLESS)
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{
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off_t length = fr->track_frames * spf(fr);
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off_t skipbegin = GAPLESS_DELAY + ((((int) fr->bsbuf[lame_offset]) << 4) | (((int) fr->bsbuf[lame_offset+1]) >> 4));
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off_t skipend = -GAPLESS_DELAY + (((((int) fr->bsbuf[lame_offset+1]) << 8) | (((int) fr->bsbuf[lame_offset+2]))) & 0xfff);
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debug3("preparing gapless mode for layer3: length %lu, skipbegin %lu, skipend %lu",
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(long unsigned)length, (long unsigned)skipbegin, (long unsigned)skipend);
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if(length > 1)
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frame_gapless_init(fr, skipbegin, (skipend < length) ? length-skipend : length);
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}
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#endif
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}
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/* switch buffer back ... */
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fr->bsbuf = fr->bsspace[fr->bsnum]+512;
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fr->bsnum = (fr->bsnum + 1) & 1;
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return 1; /* got it! */
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}
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}
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}
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return 0; /* no lame tag */
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}
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/* Just tell if the header is some mono. */
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static int header_mono(unsigned long newhead)
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{
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return ((newhead>>6)&0x3) == MPG_MD_MONO ? TRUE : FALSE;
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}
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/*
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That's a big one: read the next frame. 1 is success, <= 0 is some error
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Special error READER_MORE means: Please feed more data and try again.
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*/
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int read_frame(mpg123_handle *fr)
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{
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/* TODO: rework this thing */
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unsigned long newhead;
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off_t framepos;
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int ret;
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/* stuff that needs resetting if complete frame reading fails */
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int oldsize = fr->framesize;
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int oldphase = fr->halfphase;
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/* The counter for the search-first-header loop.
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It is persistent outside the loop to prevent seemingly endless loops
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when repeatedly headers are found that do not have valid followup headers. */
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int headcount = 0;
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fr->fsizeold=fr->framesize; /* for Layer3 */
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/* Speed-down hack: Play it again, Sam (the frame, I mean). */
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if (fr->p.halfspeed)
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{
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if(fr->halfphase) /* repeat last frame */
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{
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debug("repeat!");
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fr->to_decode = fr->to_ignore = TRUE;
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--fr->halfphase;
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fr->bitindex = 0;
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fr->wordpointer = (unsigned char *) fr->bsbuf;
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if(fr->lay == 3) memcpy (fr->bsbuf, fr->ssave, fr->ssize);
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if(fr->error_protection) fr->crc = getbits(fr, 16); /* skip crc */
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return 1;
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}
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else
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|
{
|
|
fr->halfphase = fr->p.halfspeed - 1;
|
|
}
|
|
}
|
|
|
|
read_again:
|
|
/* In case we are looping to find a valid frame, discard any buffered data before the current position.
|
|
This is essential to prevent endless looping, always going back to the beginning when feeder buffer is exhausted. */
|
|
if(fr->rd->forget != NULL) fr->rd->forget(fr);
|
|
|
|
debug2("trying to get frame %"OFF_P" at %"OFF_P, (off_p)fr->num+1, (off_p)fr->rd->tell(fr));
|
|
if((ret = fr->rd->head_read(fr,&newhead)) <= 0){ debug("need more?"); goto read_frame_bad;}
|
|
|
|
init_resync:
|
|
|
|
fr->header_change = 2; /* output format change is possible... */
|
|
if(fr->oldhead) /* check a following header for change */
|
|
{
|
|
if(fr->oldhead == newhead) fr->header_change = 0;
|
|
else
|
|
/* If they have the same sample rate. Note that only is _not_ the case for the first header, as we enforce sample rate match for following frames.
|
|
So, during one stream, only change of stereoness is possible and indicated by header_change == 2. */
|
|
if((fr->oldhead & HDRSAMPMASK) == (newhead & HDRSAMPMASK))
|
|
{
|
|
/* Now if both channel modes are mono or both stereo, it's no big deal. */
|
|
if( header_mono(fr->oldhead) == header_mono(newhead))
|
|
fr->header_change = 1;
|
|
}
|
|
}
|
|
|
|
#ifdef SKIP_JUNK
|
|
/* watch out for junk/tags on beginning of stream by invalid header */
|
|
if(!fr->firsthead && !head_check(newhead)) {
|
|
|
|
/* check for id3v2; first three bytes (of 4) are "ID3" */
|
|
if((newhead & (unsigned long) 0xffffff00) == (unsigned long) 0x49443300)
|
|
{
|
|
int id3ret = 0;
|
|
id3ret = parse_new_id3(fr, newhead);
|
|
if (id3ret < 0){ debug("need more?"); ret = id3ret; goto read_frame_bad; }
|
|
#ifndef NO_ID3V2
|
|
else if(id3ret > 0){ debug("got ID3v2"); fr->metaflags |= MPG123_NEW_ID3|MPG123_ID3; }
|
|
else debug("no useful ID3v2");
|
|
#endif
|
|
|
|
fr->oldhead = 0;
|
|
goto read_again; /* Also in case of invalid ID3 tag (ret==0), try to get on track again. */
|
|
}
|
|
else if(VERBOSE2 && fr->silent_resync == 0) fprintf(stderr,"Note: Junk at the beginning (0x%08lx)\n",newhead);
|
|
|
|
/* I even saw RIFF headers at the beginning of MPEG streams ;( */
|
|
if(newhead == ('R'<<24)+('I'<<16)+('F'<<8)+'F') {
|
|
if(VERBOSE2 && fr->silent_resync == 0) fprintf(stderr, "Note: Looks like a RIFF header.\n");
|
|
|
|
if((ret=fr->rd->head_read(fr,&newhead))<=0){ debug("need more?"); goto read_frame_bad; }
|
|
|
|
while(newhead != ('d'<<24)+('a'<<16)+('t'<<8)+'a')
|
|
{
|
|
if((ret=fr->rd->head_shift(fr,&newhead))<=0){ debug("need more?"); goto read_frame_bad; }
|
|
}
|
|
if((ret=fr->rd->head_read(fr,&newhead))<=0){ debug("need more?"); goto read_frame_bad; }
|
|
|
|
if(VERBOSE2 && fr->silent_resync == 0) fprintf(stderr,"Note: Skipped RIFF header!\n");
|
|
|
|
fr->oldhead = 0;
|
|
goto read_again;
|
|
}
|
|
/* unhandled junk... just continue search for a header */
|
|
/* step in byte steps through next 64K */
|
|
debug("searching for header...");
|
|
|
|
ret = 0; /* We will check the value after the loop. */
|
|
for(; headcount<65536; headcount++)
|
|
{
|
|
if((ret=fr->rd->head_shift(fr,&newhead))<=0){ debug("need more?"); goto read_frame_bad; }
|
|
/* if(head_check(newhead)) */
|
|
if(head_check(newhead) && (ret=decode_header(fr, newhead)))
|
|
break;
|
|
}
|
|
if(ret<0){ debug("need more?"); goto read_frame_bad; }
|
|
|
|
if(headcount == 65536)
|
|
{
|
|
if(NOQUIET) error("Giving up searching valid MPEG header after (over) 64K of junk.");
|
|
return 0;
|
|
}
|
|
else debug1("hopefully found one at %"OFF_P, (off_p)fr->rd->tell(fr));
|
|
/*
|
|
* should we additionaly check, whether a new frame starts at
|
|
* the next expected position? (some kind of read ahead)
|
|
* We could implement this easily, at least for files.
|
|
*/
|
|
}
|
|
#endif
|
|
|
|
/* first attempt of read ahead check to find the real first header; cannot believe what junk is out there! */
|
|
if(!fr->firsthead && fr->rdat.flags & (READER_SEEKABLE|READER_BUFFERED) && head_check(newhead) && (ret=decode_header(fr, newhead)))
|
|
{
|
|
unsigned long nexthead = 0;
|
|
int hd = 0;
|
|
off_t start = fr->rd->tell(fr);
|
|
if(ret<0){ debug("need more?"); goto read_frame_bad; }
|
|
|
|
debug2("doing ahead check with BPF %d at %"OFF_P, fr->framesize+4, (off_p)start);
|
|
/* step framesize bytes forward and read next possible header*/
|
|
if((ret=fr->rd->skip_bytes(fr, fr->framesize))<0)
|
|
{
|
|
if(ret==READER_ERROR && NOQUIET) error("cannot seek!");
|
|
goto read_frame_bad;
|
|
}
|
|
hd = fr->rd->head_read(fr,&nexthead);
|
|
if(hd==MPG123_NEED_MORE){ debug("need more?"); ret = hd; goto read_frame_bad; }
|
|
if((ret=fr->rd->back_bytes(fr, fr->rd->tell(fr)-start))<0)
|
|
{
|
|
if(ret==READER_ERROR && NOQUIET) error("cannot seek!");
|
|
else debug("need more?");
|
|
goto read_frame_bad;
|
|
}
|
|
debug1("After fetching next header, at %"OFF_P, (off_p)fr->rd->tell(fr));
|
|
if(!hd)
|
|
{
|
|
if(NOQUIET) warning("cannot read next header, a one-frame stream? Duh...");
|
|
}
|
|
else
|
|
{
|
|
debug2("does next header 0x%08lx match first 0x%08lx?", nexthead, newhead);
|
|
/* not allowing free format yet */
|
|
if(!head_check(nexthead) || (nexthead & HDRCMPMASK) != (newhead & HDRCMPMASK))
|
|
{
|
|
debug("No, the header was not valid, start from beginning...");
|
|
fr->oldhead = 0; /* start over */
|
|
/* try next byte for valid header */
|
|
if((ret=fr->rd->back_bytes(fr, 3))<0)
|
|
{
|
|
if(NOQUIET) error("cannot seek!");
|
|
else debug("need more?");
|
|
goto read_frame_bad;
|
|
}
|
|
goto read_again;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* why has this head check been avoided here before? */
|
|
if(!head_check(newhead))
|
|
{
|
|
/* and those ugly ID3 tags */
|
|
if((newhead & 0xffffff00) == ('T'<<24)+('A'<<16)+('G'<<8))
|
|
{
|
|
fr->id3buf[0] = (unsigned char) ((newhead >> 24) & 0xff);
|
|
fr->id3buf[1] = (unsigned char) ((newhead >> 16) & 0xff);
|
|
fr->id3buf[2] = (unsigned char) ((newhead >> 8) & 0xff);
|
|
fr->id3buf[3] = (unsigned char) ( newhead & 0xff);
|
|
if((ret=fr->rd->fullread(fr,fr->id3buf+4,124)) < 0){ debug("need more?"); goto read_frame_bad; }
|
|
fr->metaflags |= MPG123_NEW_ID3|MPG123_ID3;
|
|
fr->rdat.flags |= READER_ID3TAG; /* that marks id3v1 */
|
|
if (VERBOSE3) fprintf(stderr,"Note: Skipped ID3v1 tag.\n");
|
|
goto read_again;
|
|
}
|
|
/* duplicated code from above! */
|
|
/* check for id3v2; first three bytes (of 4) are "ID3" */
|
|
if((newhead & (unsigned long) 0xffffff00) == (unsigned long) 0x49443300)
|
|
{
|
|
int id3length = 0;
|
|
id3length = parse_new_id3(fr, newhead);
|
|
if(id3length < 0){ debug("need more?"); ret = id3length; goto read_frame_bad; }
|
|
|
|
fr->metaflags |= MPG123_NEW_ID3|MPG123_ID3;
|
|
goto read_again;
|
|
}
|
|
else if(NOQUIET && fr->silent_resync == 0)
|
|
{
|
|
fprintf(stderr,"Note: Illegal Audio-MPEG-Header 0x%08lx at offset %"OFF_P".\n",
|
|
newhead, (off_p)fr->rd->tell(fr)-4);
|
|
}
|
|
|
|
if(NOQUIET && (newhead & 0xffffff00) == ('b'<<24)+('m'<<16)+('p'<<8)) fprintf(stderr,"Note: Could be a BMP album art.\n");
|
|
/* Do resync if not forbidden by flag.
|
|
I used to have a check for not-icy-meta here, but concluded that the desync issues came from a reader bug, not the stream. */
|
|
if( !(fr->p.flags & MPG123_NO_RESYNC) )
|
|
{
|
|
long try = 0;
|
|
long limit = fr->p.resync_limit;
|
|
|
|
/* If a resync is needed the bitreservoir of previous frames is no longer valid */
|
|
fr->bitreservoir = 0;
|
|
|
|
/* TODO: make this more robust, I'd like to cat two mp3 fragments together (in a dirty way) and still have mpg123 beign able to decode all it somehow. */
|
|
if(NOQUIET && fr->silent_resync == 0) fprintf(stderr, "Note: Trying to resync...\n");
|
|
/* Read more bytes until we find something that looks
|
|
reasonably like a valid header. This is not a
|
|
perfect strategy, but it should get us back on the
|
|
track within a short time (and hopefully without
|
|
too much distortion in the audio output). */
|
|
do
|
|
{
|
|
++try;
|
|
if(limit >= 0 && try >= limit) break;
|
|
|
|
if((ret=fr->rd->head_shift(fr,&newhead)) <= 0)
|
|
{
|
|
debug("need more?");
|
|
if(NOQUIET) fprintf (stderr, "Note: Hit end of (available) data during resync.\n");
|
|
|
|
goto read_frame_bad;
|
|
}
|
|
if(VERBOSE3) debug3("resync try %li at %"OFF_P", got newhead 0x%08lx", try, (off_p)fr->rd->tell(fr), newhead);
|
|
|
|
if(!fr->oldhead)
|
|
{
|
|
debug("going to init_resync...");
|
|
goto init_resync; /* "considered harmful", eh? */
|
|
}
|
|
/* we should perhaps collect a list of valid headers that occured in file... there can be more */
|
|
/* Michael's new resync routine seems to work better with the one frame readahead (and some input buffering?) */
|
|
} while
|
|
(
|
|
!head_check(newhead) /* Simply check for any valid header... we have the readahead to get it straight now(?) */
|
|
/* (newhead & HDRCMPMASK) != (fr->oldhead & HDRCMPMASK)
|
|
&& (newhead & HDRCMPMASK) != (fr->firsthead & HDRCMPMASK)*/
|
|
);
|
|
/* too many false positives
|
|
}while (!(head_check(newhead) && decode_header(fr, newhead))); */
|
|
if(NOQUIET && fr->silent_resync == 0) fprintf (stderr, "Note: Skipped %li bytes in input.\n", try);
|
|
|
|
if(limit >= 0 && try >= limit)
|
|
{
|
|
if(NOQUIET)
|
|
error1("Giving up resync after %li bytes - your stream is not nice... (maybe increasing resync limit could help).", try);
|
|
|
|
fr->err = MPG123_RESYNC_FAIL;
|
|
return READER_ERROR;
|
|
}
|
|
else
|
|
{
|
|
debug1("Found valid header 0x%lx... unsetting firsthead to reinit stream.", newhead);
|
|
fr->firsthead = 0;
|
|
goto init_resync;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if(NOQUIET) error("not attempting to resync...");
|
|
|
|
fr->err = MPG123_OUT_OF_SYNC;
|
|
return READER_ERROR;
|
|
}
|
|
}
|
|
|
|
/* Man, that code looks awfully redundant...
|
|
I need to untangle the spaghetti here in a future version. */
|
|
if(!fr->firsthead)
|
|
{
|
|
ret=decode_header(fr,newhead);
|
|
if(ret == 0)
|
|
{
|
|
if(NOQUIET) error("decode header failed before first valid one, going to read again");
|
|
|
|
goto read_again;
|
|
}
|
|
else if(ret < 0){ debug("need more?"); goto read_frame_bad; }
|
|
}
|
|
else
|
|
{
|
|
ret=decode_header(fr,newhead);
|
|
if(ret == 0)
|
|
{
|
|
if(NOQUIET) error("decode header failed - goto resync");
|
|
/* return 0; */
|
|
goto init_resync;
|
|
}
|
|
else if(ret < 0){ debug("need more?"); goto read_frame_bad; }
|
|
}
|
|
|
|
/* if filepos is invalid, so is framepos */
|
|
framepos = fr->rd->tell(fr) - 4;
|
|
/* flip/init buffer for Layer 3 */
|
|
{
|
|
unsigned char *newbuf = fr->bsspace[fr->bsnum]+512;
|
|
/* read main data into memory */
|
|
if((ret=fr->rd->read_frame_body(fr,newbuf,fr->framesize))<0)
|
|
{
|
|
/* if failed: flip back */
|
|
debug("need more?");
|
|
goto read_frame_bad;
|
|
}
|
|
fr->bsbufold = fr->bsbuf;
|
|
fr->bsbuf = newbuf;
|
|
}
|
|
fr->bsnum = (fr->bsnum + 1) & 1;
|
|
|
|
if(!fr->firsthead)
|
|
{
|
|
fr->firsthead = newhead; /* _now_ it's time to store it... the first real header */
|
|
/* This is the first header of our current stream segment.
|
|
It is only the actual first header of the whole stream when fr->num is still below zero!
|
|
Think of resyncs where firsthead has been reset for format flexibility. */
|
|
if(fr->num < 0)
|
|
{
|
|
fr->audio_start = framepos;
|
|
/* Only check for LAME tag at beginning of whole stream
|
|
... when there indeed is one in between, it's the user's problem. */
|
|
if(fr->lay == 3 && check_lame_tag(fr) == 1)
|
|
{ /* ...in practice, Xing/LAME tags are layer 3 only. */
|
|
if(fr->rd->forget != NULL) fr->rd->forget(fr);
|
|
|
|
fr->oldhead = 0;
|
|
goto read_again;
|
|
}
|
|
/* now adjust volume */
|
|
do_rva(fr);
|
|
}
|
|
|
|
debug2("fr->firsthead: %08lx, audio_start: %li", fr->firsthead, (long int)fr->audio_start);
|
|
}
|
|
|
|
fr->bitindex = 0;
|
|
fr->wordpointer = (unsigned char *) fr->bsbuf;
|
|
/* Question: How bad does the floating point value get with repeated recomputation?
|
|
Also, considering that we can play the file or parts of many times. */
|
|
if(++fr->mean_frames != 0)
|
|
{
|
|
fr->mean_framesize = ((fr->mean_frames-1)*fr->mean_framesize+compute_bpf(fr)) / fr->mean_frames ;
|
|
}
|
|
++fr->num; /* 0 for first frame! */
|
|
debug4("Frame %"OFF_P" %08lx %i, next filepos=%"OFF_P,
|
|
(off_p)fr->num, newhead, fr->framesize, (off_p)fr->rd->tell(fr));
|
|
|
|
/* save for repetition */
|
|
if(fr->p.halfspeed && fr->lay == 3)
|
|
{
|
|
debug("halfspeed - reusing old bsbuf ");
|
|
memcpy (fr->ssave, fr->bsbuf, fr->ssize);
|
|
}
|
|
|
|
/* index the position */
|
|
#ifdef FRAME_INDEX
|
|
/* Keep track of true frame positions in our frame index.
|
|
but only do so when we are sure that the frame number is accurate... */
|
|
if(fr->accurate && FI_NEXT(fr->index, fr->num))
|
|
fi_add(&fr->index, framepos);
|
|
#endif
|
|
|
|
if(fr->silent_resync > 0) --fr->silent_resync;
|
|
|
|
if(fr->rd->forget != NULL) fr->rd->forget(fr);
|
|
|
|
fr->to_decode = fr->to_ignore = TRUE;
|
|
if(fr->error_protection) fr->crc = getbits(fr, 16); /* skip crc */
|
|
|
|
return 1;
|
|
read_frame_bad:
|
|
/* Also if we searched for valid data in vain, we can forget skipped data.
|
|
Otherwise, the feeder would hold every dead old byte in memory until the first valid frame! */
|
|
if(fr->rd->forget != NULL) fr->rd->forget(fr);
|
|
|
|
fr->silent_resync = 0;
|
|
if(fr->err == MPG123_OK) fr->err = MPG123_ERR_READER;
|
|
fr->framesize = oldsize;
|
|
fr->halfphase = oldphase;
|
|
/* That return code might be inherited from some feeder action, or reader error. */
|
|
return ret;
|
|
}
|
|
|
|
|
|
/*
|
|
* read ahead and find the next MPEG header, to guess framesize
|
|
* return value: success code
|
|
* 1: found a valid frame size (stored in the handle).
|
|
* <0: error codes, possibly from feeder buffer (NEED_MORE)
|
|
* 0: cannot get the framesize for some reason and shall silentry try the next possible header (if this is no free format stream after all...)
|
|
*/
|
|
static int guess_freeformat_framesize(mpg123_handle *fr)
|
|
{
|
|
long i;
|
|
int ret;
|
|
unsigned long head;
|
|
if(!(fr->rdat.flags & (READER_SEEKABLE|READER_BUFFERED)))
|
|
{
|
|
if(NOQUIET) error("Cannot look for freeformat frame size with non-seekable and non-buffered stream!");
|
|
|
|
return 0;
|
|
}
|
|
if((ret=fr->rd->head_read(fr,&head))<=0)
|
|
return ret;
|
|
|
|
/* We are already 4 bytes into it */
|
|
/* fix that limit to be absolute for the first header search! */
|
|
for(i=4;i<65536;i++) {
|
|
if((ret=fr->rd->head_shift(fr,&head))<=0)
|
|
{
|
|
return ret;
|
|
}
|
|
if(head_check(head))
|
|
{
|
|
int sampling_frequency,mpeg25,lsf;
|
|
|
|
if(head & (1<<20))
|
|
{
|
|
lsf = (head & (1<<19)) ? 0x0 : 0x1;
|
|
mpeg25 = 0;
|
|
}
|
|
else
|
|
{
|
|
lsf = 1;
|
|
mpeg25 = 1;
|
|
}
|
|
|
|
if(mpeg25)
|
|
sampling_frequency = 6 + ((head>>10)&0x3);
|
|
else
|
|
sampling_frequency = ((head>>10)&0x3) + (lsf*3);
|
|
|
|
if((lsf==fr->lsf) && (mpeg25==fr->mpeg25) && (sampling_frequency == fr->sampling_frequency))
|
|
{
|
|
fr->rd->back_bytes(fr,i+1);
|
|
fr->framesize = i-3;
|
|
return 1; /* Success! */
|
|
}
|
|
}
|
|
}
|
|
fr->rd->back_bytes(fr,i);
|
|
return 0;
|
|
}
|
|
|
|
|
|
/*
|
|
* decode a header and write the information
|
|
* into the frame structure
|
|
* Return values are compatible with those of read_frame, namely:
|
|
* 1: success
|
|
* 0: no valid header
|
|
* <0: some error
|
|
*/
|
|
static int decode_header(mpg123_handle *fr,unsigned long newhead)
|
|
{
|
|
if(!head_check(newhead))
|
|
{
|
|
if(NOQUIET) error("tried to decode obviously invalid header");
|
|
|
|
return 0;
|
|
}
|
|
if( newhead & (1<<20) )
|
|
{
|
|
fr->lsf = (newhead & (1<<19)) ? 0x0 : 0x1;
|
|
fr->mpeg25 = 0;
|
|
}
|
|
else
|
|
{
|
|
fr->lsf = 1;
|
|
fr->mpeg25 = 1;
|
|
}
|
|
|
|
if( (fr->p.flags & MPG123_NO_RESYNC) || !fr->oldhead
|
|
|| (((fr->oldhead>>19)&0x3) ^ ((newhead>>19)&0x3)) )
|
|
{
|
|
/* If "tryresync" is false, assume that certain
|
|
parameters do not change within the stream!
|
|
Force an update if lsf or mpeg25 settings
|
|
have changed. */
|
|
fr->lay = 4-((newhead>>17)&3);
|
|
if( ((newhead>>10)&0x3) == 0x3)
|
|
{
|
|
if(NOQUIET) error("Stream error");
|
|
|
|
return 0; /* exit() here really is too much, isn't it? */
|
|
}
|
|
if(fr->mpeg25)
|
|
fr->sampling_frequency = 6 + ((newhead>>10)&0x3);
|
|
else
|
|
fr->sampling_frequency = ((newhead>>10)&0x3) + (fr->lsf*3);
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
if((((newhead>>16)&0x1)^0x1) != fr->error_protection) debug("changed crc bit!");
|
|
#endif
|
|
fr->error_protection = ((newhead>>16)&0x1)^0x1; /* seen a file where this varies (old lame tag without crc, track with crc) */
|
|
fr->bitrate_index = ((newhead>>12)&0xf);
|
|
fr->padding = ((newhead>>9)&0x1);
|
|
fr->extension = ((newhead>>8)&0x1);
|
|
fr->mode = ((newhead>>6)&0x3);
|
|
fr->mode_ext = ((newhead>>4)&0x3);
|
|
fr->copyright = ((newhead>>3)&0x1);
|
|
fr->original = ((newhead>>2)&0x1);
|
|
fr->emphasis = newhead & 0x3;
|
|
fr->freeformat = free_format_header(newhead);
|
|
|
|
fr->stereo = (fr->mode == MPG_MD_MONO) ? 1 : 2;
|
|
|
|
fr->oldhead = newhead;
|
|
|
|
/* we can't use tabsel_123 for freeformat, so trying to guess framesize... */
|
|
if(fr->freeformat)
|
|
{
|
|
/* when we first encounter the frame with freeformat, guess framesize */
|
|
if(fr->freeformat_framesize < 0)
|
|
{
|
|
int ret;
|
|
ret = guess_freeformat_framesize(fr);
|
|
if(ret>0)
|
|
{
|
|
fr->freeformat_framesize = fr->framesize - fr->padding;
|
|
if(VERBOSE2)
|
|
fprintf(stderr, "Note: free format frame size %li\n", fr->freeformat_framesize);
|
|
}
|
|
else
|
|
{
|
|
if(ret == MPG123_NEED_MORE)
|
|
debug("Need more data to guess free format frame size.");
|
|
else
|
|
error("Encountered free format header, but failed to guess frame size.");
|
|
return ret;
|
|
}
|
|
}
|
|
/* freeformat should be CBR, so the same framesize can be used at the 2nd reading or later */
|
|
else
|
|
{
|
|
fr->framesize = fr->freeformat_framesize + fr->padding;
|
|
}
|
|
}
|
|
|
|
switch(fr->lay)
|
|
{
|
|
#ifndef NO_LAYER1
|
|
case 1:
|
|
fr->do_layer = do_layer1;
|
|
if(!fr->freeformat)
|
|
{
|
|
fr->framesize = (long) tabsel_123[fr->lsf][0][fr->bitrate_index] * 12000;
|
|
fr->framesize /= freqs[fr->sampling_frequency];
|
|
fr->framesize = ((fr->framesize+fr->padding)<<2)-4;
|
|
}
|
|
break;
|
|
#endif
|
|
#ifndef NO_LAYER2
|
|
case 2:
|
|
fr->do_layer = do_layer2;
|
|
if(!fr->freeformat)
|
|
{
|
|
debug2("bitrate index: %i (%i)", fr->bitrate_index, tabsel_123[fr->lsf][1][fr->bitrate_index] );
|
|
fr->framesize = (long) tabsel_123[fr->lsf][1][fr->bitrate_index] * 144000;
|
|
fr->framesize /= freqs[fr->sampling_frequency];
|
|
fr->framesize += fr->padding - 4;
|
|
}
|
|
break;
|
|
#endif
|
|
#ifndef NO_LAYER3
|
|
case 3:
|
|
fr->do_layer = do_layer3;
|
|
if(fr->lsf)
|
|
fr->ssize = (fr->stereo == 1) ? 9 : 17;
|
|
else
|
|
fr->ssize = (fr->stereo == 1) ? 17 : 32;
|
|
|
|
if(fr->error_protection)
|
|
fr->ssize += 2;
|
|
|
|
if(!fr->freeformat)
|
|
{
|
|
fr->framesize = (long) tabsel_123[fr->lsf][2][fr->bitrate_index] * 144000;
|
|
fr->framesize /= freqs[fr->sampling_frequency]<<(fr->lsf);
|
|
fr->framesize = fr->framesize + fr->padding - 4;
|
|
}
|
|
break;
|
|
#endif
|
|
default:
|
|
if(NOQUIET) error1("Layer type %i not supported in this build!", fr->lay);
|
|
|
|
return 0;
|
|
}
|
|
if (fr->framesize > MAXFRAMESIZE)
|
|
{
|
|
if(NOQUIET) error1("Frame size too big: %d", fr->framesize+4-fr->padding);
|
|
|
|
return (0);
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
void set_pointer(mpg123_handle *fr, long backstep)
|
|
{
|
|
fr->wordpointer = fr->bsbuf + fr->ssize - backstep;
|
|
if (backstep)
|
|
memcpy(fr->wordpointer,fr->bsbufold+fr->fsizeold-backstep,backstep);
|
|
|
|
fr->bitindex = 0;
|
|
}
|
|
|
|
/********************************/
|
|
|
|
double compute_bpf(mpg123_handle *fr)
|
|
{
|
|
double bpf;
|
|
|
|
switch(fr->lay)
|
|
{
|
|
case 1:
|
|
bpf = tabsel_123[fr->lsf][0][fr->bitrate_index];
|
|
bpf *= 12000.0 * 4.0;
|
|
bpf /= freqs[fr->sampling_frequency] <<(fr->lsf);
|
|
break;
|
|
case 2:
|
|
case 3:
|
|
bpf = tabsel_123[fr->lsf][fr->lay-1][fr->bitrate_index];
|
|
bpf *= 144000;
|
|
bpf /= freqs[fr->sampling_frequency] << (fr->lsf);
|
|
break;
|
|
default:
|
|
bpf = 1.0;
|
|
}
|
|
|
|
return bpf;
|
|
}
|
|
|
|
double attribute_align_arg mpg123_tpf(mpg123_handle *fr)
|
|
{
|
|
static int bs[4] = { 0,384,1152,1152 };
|
|
double tpf;
|
|
if(fr == NULL) return -1;
|
|
|
|
tpf = (double) bs[fr->lay];
|
|
tpf /= freqs[fr->sampling_frequency] << (fr->lsf);
|
|
return tpf;
|
|
}
|
|
|
|
int attribute_align_arg mpg123_position(mpg123_handle *fr, off_t no, off_t buffsize,
|
|
off_t *current_frame, off_t *frames_left,
|
|
double *current_seconds, double *seconds_left)
|
|
{
|
|
double tpf;
|
|
double dt = 0.0;
|
|
off_t cur, left;
|
|
double curs, lefts;
|
|
|
|
if(!fr || !fr->rd) /* Isn't this too paranoid? */
|
|
{
|
|
debug("reader troubles!");
|
|
return MPG123_ERR;
|
|
}
|
|
|
|
no += fr->num; /* no starts out as offset */
|
|
cur = no;
|
|
tpf = mpg123_tpf(fr);
|
|
if(buffsize > 0 && fr->af.rate > 0 && fr->af.channels > 0)
|
|
{
|
|
dt = (double) buffsize / fr->af.rate / fr->af.channels;
|
|
if(fr->af.encoding & MPG123_ENC_16) dt *= 0.5;
|
|
}
|
|
|
|
left = 0;
|
|
|
|
if((fr->track_frames != 0) && (fr->track_frames >= fr->num)) left = no < fr->track_frames ? fr->track_frames - no : 0;
|
|
else
|
|
if(fr->rdat.filelen >= 0)
|
|
{
|
|
double bpf;
|
|
off_t t = fr->rd->tell(fr);
|
|
bpf = fr->mean_framesize ? fr->mean_framesize : compute_bpf(fr);
|
|
left = (off_t)((double)(fr->rdat.filelen-t)/bpf);
|
|
/* no can be different for prophetic purposes, file pointer is always associated with fr->num! */
|
|
if(fr->num != no)
|
|
{
|
|
if(fr->num > no) left += fr->num - no;
|
|
else
|
|
{
|
|
if(left >= (no - fr->num)) left -= no - fr->num;
|
|
else left = 0; /* uh, oh! */
|
|
}
|
|
}
|
|
/* I totally don't understand why we should re-estimate the given correct(?) value */
|
|
/* fr->num = (unsigned long)((double)t/bpf); */
|
|
}
|
|
|
|
/* beginning with 0 or 1?*/
|
|
curs = (double) no*tpf-dt;
|
|
lefts = (double)left*tpf+dt;
|
|
#if 0
|
|
curs = curs < 0 ? 0.0 : curs;
|
|
#endif
|
|
if(left < 0 || lefts < 0)
|
|
{ /* That is the case for non-seekable streams. */
|
|
left = 0;
|
|
lefts = 0.0;
|
|
}
|
|
if(current_frame != NULL) *current_frame = cur;
|
|
if(frames_left != NULL) *frames_left = left;
|
|
if(current_seconds != NULL) *current_seconds = curs;
|
|
if(seconds_left != NULL) *seconds_left = lefts;
|
|
return MPG123_OK;
|
|
}
|
|
|
|
int get_songlen(mpg123_handle *fr,int no)
|
|
{
|
|
double tpf;
|
|
|
|
if(!fr)
|
|
return 0;
|
|
|
|
if(no < 0) {
|
|
if(!fr->rd || fr->rdat.filelen < 0)
|
|
return 0;
|
|
no = (int) ((double) fr->rdat.filelen / compute_bpf(fr));
|
|
}
|
|
|
|
tpf = mpg123_tpf(fr);
|
|
return (int) (no*tpf);
|
|
}
|