diff options
Diffstat (limited to 'libmpdemux/parse_es.c')
| -rw-r--r-- | libmpdemux/parse_es.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/libmpdemux/parse_es.c b/libmpdemux/parse_es.c index 4dc20b86fd..05507a495a 100644 --- a/libmpdemux/parse_es.c +++ b/libmpdemux/parse_es.c @@ -18,6 +18,7 @@ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ +#include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> @@ -114,3 +115,44 @@ int skip_video_packet(demux_stream_t *ds){ // SYNC AGAIN: return sync_video_packet(ds); } + +/* stripped down version of a52_syncinfo() from liba52 + * copyright belongs to Michel Lespinasse <walken@zoy.org> + * and Aaron Holtzman <aholtzma@ess.engr.uvic.ca> */ +int mp_a52_framesize(uint8_t * buf, int *srate) +{ + int rate[] = { 32, 40, 48, 56, 64, 80, 96, 112, + 128, 160, 192, 224, 256, 320, 384, 448, + 512, 576, 640 + }; + uint8_t halfrate[12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3 }; + int frmsizecod, bitrate, half; + + if ((buf[0] != 0x0b) || (buf[1] != 0x77)) /* syncword */ + return 0; + + if (buf[5] >= 0x60) /* bsid >= 12 */ + return 0; + + half = halfrate[buf[5] >> 3]; + + frmsizecod = buf[4] & 63; + if (frmsizecod >= 38) + return 0; + + bitrate = rate[frmsizecod >> 1]; + + switch (buf[4] & 0xc0) { + case 0: /* 48 KHz */ + *srate = 48000 >> half; + return 4 * bitrate; + case 0x40: /* 44.1 KHz */ + *srate = 44100 >> half; + return 2 * (320 * bitrate / 147 + (frmsizecod & 1)); + case 0x80: /* 32 KHz */ + *srate = 32000 >> half; + return 6 * bitrate; + } + + return 0; +} |