[MPlayer-dev-eng] Re: [Patch] Audio detection
Michael Behrisch
behrisch at informatik.hu-berlin.de
Fri Mar 19 14:39:46 CET 2004
> No, i'm sorry :( But i can't find the patch anymore. Could you resend it ?
Here it is
Michael
-------------- next part --------------
--- libmpdemux/demux_audio.old 2003-10-09 10:02:45.000000000 +0200
+++ libmpdemux/demux_audio.c 2004-02-10 09:49:35.000000000 +0100
@@ -21,6 +21,7 @@
#define HDR_SIZE 4
+#define MIN_VALID_HEADERS 6
typedef struct da_priv {
int frmt;
@@ -37,7 +38,8 @@
stream_t *s;
sh_audio_t* sh_audio;
uint8_t hdr[HDR_SIZE];
- int st_pos = 0,frmt = 0, n = 0, pos = 0, step, mp3_freq,mp3_chans;
+ int frmt = 0, n = 0, pos = 0, bytes_to_read = HDR_SIZE;
+ int len, mp3_freq, mp3_chans;
da_priv_t* priv;
#ifdef MP_DEBUG
assert(demuxer != NULL);
@@ -46,49 +48,59 @@
s = demuxer->stream;
- while(n < 5 && ! s->eof) {
- st_pos = stream_tell(s);
- step = 1;
- if(pos < HDR_SIZE) {
- stream_read(s,&hdr[pos],HDR_SIZE-pos);
- pos = HDR_SIZE;
- }
+ while(n < 50 && ! s->eof) {
+ pos = stream_tell(s);
+ stream_read(s,&hdr[HDR_SIZE-bytes_to_read],bytes_to_read);
+ bytes_to_read = 1;
if( hdr[0] == 'R' && hdr[1] == 'I' && hdr[2] == 'F' && hdr[3] == 'F' ) {
stream_skip(s,4);
- if(s->eof)
- break;
- stream_read(s,hdr,4);
- if(s->eof)
- break;
+ if(s->eof) break;
+ stream_read(s,hdr,HDR_SIZE);
+ if(s->eof) break;
if(hdr[0] != 'W' || hdr[1] != 'A' || hdr[2] != 'V' || hdr[3] != 'E' )
stream_skip(s,-8);
else
// We found wav header. Now we can have 'fmt ' or a mp3 header
// empty the buffer
- step = 4;
+ bytes_to_read = HDR_SIZE;
} else if( hdr[0] == 'I' && hdr[1] == 'D' && hdr[2] == '3' && (hdr[3] >= 2)) {
- int len;
stream_skip(s,2);
- stream_read(s,hdr,4);
+ if(s->eof) break;
+ stream_read(s,hdr,HDR_SIZE);
+ if(s->eof) break;
len = (hdr[0]<<21) | (hdr[1]<<14) | (hdr[2]<<7) | hdr[3];
stream_skip(s,len);
- step = 4;
+ bytes_to_read = HDR_SIZE;
} else if( hdr[0] == 'f' && hdr[1] == 'm' && hdr[2] == 't' && hdr[3] == ' ' ) {
frmt = WAV;
break;
- } else if((n = mp_get_mp3_header(hdr,&mp3_chans,&mp3_freq)) > 0) {
+ } else if((len = mp_get_mp3_header(hdr,&mp3_chans,&mp3_freq)) > 20) {
+ int i, mp3_freq2, mp3_chans2;
+ for(i = 1; i < MIN_VALID_HEADERS ; i++) {
+ stream_skip(s,len-HDR_SIZE);
+ if(s->eof) break;
+ stream_read(s,hdr,HDR_SIZE);
+ if(s->eof) break;
+ len = mp_get_mp3_header(hdr,&mp3_chans2,&mp3_freq2);
+ if(len < 21 || mp3_chans != mp3_chans2 || mp3_freq != mp3_freq2) break;
+ }
+ if(i == MIN_VALID_HEADERS) {
frmt = MP3;
break;
+ }
+ if(s->eof || !s->end_pos) break;
+ stream_seek(s, pos+1);
+ bytes_to_read = HDR_SIZE;
} else if( hdr[0] == 'f' && hdr[1] == 'L' && hdr[2] == 'a' && hdr[3] == 'C' ) {
frmt = fLaC;
stream_skip(s,-4);
break;
}
// Add here some other audio format detection
- if(step < HDR_SIZE)
- memmove(hdr,&hdr[step],HDR_SIZE-step);
- pos -= step;
+ if(bytes_to_read < HDR_SIZE)
+ memmove(hdr,&hdr[bytes_to_read],HDR_SIZE-bytes_to_read);
+ n++;
}
if(!frmt)
@@ -99,7 +111,7 @@
switch(frmt) {
case MP3:
sh_audio->format = 0x55;
- demuxer->movi_start = st_pos-HDR_SIZE+n;
+ demuxer->movi_start = pos; // first frame gets skipped in mp3lib
sh_audio->audio.dwSampleSize= 0;
sh_audio->audio.dwScale = 1152;
sh_audio->audio.dwRate = mp3_freq;
@@ -110,6 +122,7 @@
sh_audio->wf->nBlockAlign = 1152;
sh_audio->wf->wBitsPerSample = 16;
sh_audio->wf->cbSize = 0;
+ //following loop can be removed after testing new detection
for(n = 0; n < 5 ; n++) {
pos = mp_decode_mp3_header(hdr);
if(pos < 0)
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