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mpv/libmpdemux/mp3_hdr.c
wm4 c323592c3a libmpdemux: add back demux_mpg
Apparently this was needed for good DVD playback.

This demuxer has been removed in 1fde09db6f. All code added comes
from the revision before that. Some other bits have been removed in
later commits, and are added back as well.

Usage of memalign() is replaced by av_malloc(). As far as I can tell,
this memory is never free'd or reallocated, so no calls to av_free()
have been added.

The code re-added to video.c is plain horrible, full of code
duplication, full of demuxer/codecs specifics, but apparently needed.

Unrelated to re-adding the demuxer, re-add one codepath for
DEMUXER_TYPE_TV, which was accidentally removed in the same commit
demux_mpg was removed.

The closed captions decoder is not re-added.
2012-09-18 21:07:30 +02:00

145 lines
4.3 KiB
C

/*
* This file is part of MPlayer.
*
* MPlayer is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* MPlayer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdio.h>
#include "config.h"
#include "mp3_hdr.h"
#include "mp_msg.h"
//----------------------- mp3 audio frame header parser -----------------------
static int tabsel_123[2][3][16] = {
{ {0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,0},
{0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,0},
{0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,0} },
{ {0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,0},
{0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,0},
{0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,0} }
};
static long freqs[9] = { 44100, 48000, 32000, // MPEG 1.0
22050, 24000, 16000, // MPEG 2.0
11025, 12000, 8000}; // MPEG 2.5
/*
* return frame size or -1 (bad frame)
*/
int mp_get_mp3_header(unsigned char* hbuf,int* chans, int* srate, int* spf, int* mpa_layer, int* br){
int stereo,ssize,lsf,framesize,padding,bitrate_index,sampling_frequency, divisor;
int bitrate;
int layer, mult[3] = { 12000, 144000, 144000 };
unsigned long newhead =
hbuf[0] << 24 |
hbuf[1] << 16 |
hbuf[2] << 8 |
hbuf[3];
// printf("head=0x%08X\n",newhead);
// head_check:
if( (newhead & 0xffe00000) != 0xffe00000 ){
mp_msg(MSGT_DEMUXER,MSGL_DBG2,"head_check failed\n");
return -1;
}
layer = 4-((newhead>>17)&3);
if(layer==4){
mp_msg(MSGT_DEMUXER,MSGL_DBG2,"not layer-1/2/3\n");
return -1;
}
sampling_frequency = ((newhead>>10)&0x3); // valid: 0..2
if(sampling_frequency==3){
mp_msg(MSGT_DEMUXER,MSGL_DBG2,"invalid sampling_frequency\n");
return -1;
}
if( newhead & ((long)1<<20) ) {
// MPEG 1.0 (lsf==0) or MPEG 2.0 (lsf==1)
lsf = (newhead & ((long)1<<19)) ? 0x0 : 0x1;
sampling_frequency += (lsf*3);
} else {
// MPEG 2.5
lsf = 1;
sampling_frequency += 6;
}
// crc = ((newhead>>16)&0x1)^0x1;
bitrate_index = ((newhead>>12)&0xf); // valid: 1..14
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;
stereo = ( (((newhead>>6)&0x3)) == 3) ? 1 : 2;
// !checked later through tabsel_123[]!
// if(!bitrate_index || bitrate_index==15){
// mp_msg(MSGT_DEMUXER,MSGL_DBG2,"Free format not supported.\n");
// return -1;
// }
if(lsf)
ssize = (stereo == 1) ? 9 : 17;
else
ssize = (stereo == 1) ? 17 : 32;
if(!((newhead>>16)&0x1)) ssize += 2; // CRC
bitrate = tabsel_123[lsf][layer-1][bitrate_index];
framesize = bitrate * mult[layer-1];
mp_msg(MSGT_DEMUXER,MSGL_DBG2,"FRAMESIZE: %d, layer: %d, bitrate: %d, mult: %d\n",
framesize, layer, tabsel_123[lsf][layer-1][bitrate_index], mult[layer-1]);
if(!framesize){
mp_msg(MSGT_DEMUXER,MSGL_DBG2,"invalid framesize/bitrate_index\n");
return -1;
}
divisor = (layer == 3 ? (freqs[sampling_frequency] << lsf) : freqs[sampling_frequency]);
framesize /= divisor;
if(layer==1)
framesize = (framesize+padding)*4;
else
framesize += padding;
// if(framesize<=0 || framesize>MAXFRAMESIZE) return FALSE;
if(srate) {
*srate = freqs[sampling_frequency];
if(spf) {
if(layer == 1)
*spf = 384;
else if(layer == 2)
*spf = 1152;
else if(*srate < 32000)
*spf = 576;
else
*spf = 1152;
}
}
if(mpa_layer) *mpa_layer = layer;
if(chans) *chans = stereo;
if(br) *br = bitrate;
return framesize;
}