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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"
#include "mp_msg.h"
#include "help_mp.h"
#include "stream/stream.h"
#include "demuxer.h"
#include "parse_es.h"
#include "stheader.h"
#include "ms_hdr.h"
typedef struct {
uint8_t *buf;
uint64_t size; /// amount of time of data packets pushed to demuxer->audio (in bytes)
float time; /// amount of time elapsed based upon samples_per_frame/sample_rate (in milliseconds)
float last_pts; /// last pts seen
int bitrate; /// bitrate computed as size/time
} aac_priv_t;
/// \param srate (out) sample rate
/// \param num (out) number of audio frames in this ADTS frame
/// \return size of the ADTS frame in bytes
/// aac_parse_frames needs a buffer at least 8 bytes long
int aac_parse_frame(uint8_t *buf, int *srate, int *num);
static int demux_aac_init(demuxer_t *demuxer)
{
aac_priv_t *priv;
priv = calloc(1, sizeof(aac_priv_t));
if(!priv)
return 0;
priv->buf = (uint8_t*) malloc(8);
if(!priv->buf)
{
free(priv);
return 0;
}
demuxer->priv = priv;
return 1;
}
static void demux_close_aac(demuxer_t *demuxer)
{
aac_priv_t *priv = (aac_priv_t *) demuxer->priv;
if(!priv)
return;
if(priv->buf)
free(priv->buf);
free(demuxer->priv);
return;
}
/// returns DEMUXER_TYPE_AAC if it finds 8 ADTS frames in 32768 bytes, 0 otherwise
static int demux_aac_probe(demuxer_t *demuxer)
{
int cnt = 0, c, len, srate, num;
off_t init, probed;
aac_priv_t *priv;
if(! demux_aac_init(demuxer))
{
mp_msg(MSGT_DEMUX, MSGL_ERR, "COULDN'T INIT aac_demux, exit\n");
return 0;
}
priv = (aac_priv_t *) demuxer->priv;
init = probed = stream_tell(demuxer->stream);
while(probed-init <= 32768 && cnt < 8)
{
c = 0;
while(c != 0xFF)
{
c = stream_read_char(demuxer->stream);
if(c < 0)
goto fail;
}
priv->buf[0] = 0xFF;
if(stream_read(demuxer->stream, &(priv->buf[1]), 7) < 7)
goto fail;
len = aac_parse_frame(priv->buf, &srate, &num);
if(len > 0)
{
cnt++;
stream_skip(demuxer->stream, len - 8);
}
probed = stream_tell(demuxer->stream);
}
stream_seek(demuxer->stream, init);
if(cnt < 8)
goto fail;
mp_msg(MSGT_DEMUX, MSGL_V, "demux_aac_probe, INIT: %"PRIu64", PROBED: %"PRIu64", cnt: %d\n", init, probed, cnt);
return DEMUXER_TYPE_AAC;
fail:
mp_msg(MSGT_DEMUX, MSGL_V, "demux_aac_probe, failed to detect an AAC stream\n");
return 0;
}
static demuxer_t* demux_aac_open(demuxer_t *demuxer)
{
sh_audio_t *sh;
sh = new_sh_audio(demuxer, 0);
sh->ds = demuxer->audio;
sh->format = mmioFOURCC('M', 'P', '4', 'A');
demuxer->audio->id = 0;
demuxer->audio->sh = sh;
demuxer->filepos = stream_tell(demuxer->stream);
return demuxer;
}
static int demux_aac_fill_buffer(demuxer_t *demuxer, demux_stream_t *ds)
{
aac_priv_t *priv = (aac_priv_t *) demuxer->priv;
demux_packet_t *dp;
int c1, c2, len, srate, num;
float tm = 0;
if(demuxer->stream->eof || (demuxer->movi_end && stream_tell(demuxer->stream) >= demuxer->movi_end))
return 0;
while(! demuxer->stream->eof)
{
c1 = c2 = 0;
while(c1 != 0xFF)
{
c1 = stream_read_char(demuxer->stream);
if(c1 < 0)
return 0;
}
c2 = stream_read_char(demuxer->stream);
if(c2 < 0)
return 0;
if((c2 & 0xF6) != 0xF0)
continue;
priv->buf[0] = (unsigned char) c1;
priv->buf[1] = (unsigned char) c2;
if(stream_read(demuxer->stream, &(priv->buf[2]), 6) < 6)
return 0;
len = aac_parse_frame(priv->buf, &srate, &num);
if(len > 0)
{
dp = new_demux_packet(len);
if(! dp)
{
mp_msg(MSGT_DEMUX, MSGL_ERR, "fill_buffer, NEW_ADD_PACKET(%d)FAILED\n", len);
return 0;
}
memcpy(dp->buffer, priv->buf, 8);
stream_read(demuxer->stream, &(dp->buffer[8]), len-8);
if(srate)
tm = (float) (num * 1024.0/srate);
priv->last_pts += tm;
dp->pts = priv->last_pts;
//fprintf(stderr, "\nPTS: %.3f\n", dp->pts);
ds_add_packet(demuxer->audio, dp);
priv->size += len;
priv->time += tm;
priv->bitrate = (int) (priv->size / priv->time);
demuxer->filepos = stream_tell(demuxer->stream);
return len;
}
else
stream_skip(demuxer->stream, -6);
}
return 0;
}
//This is an almost verbatim copy of high_res_mp3_seek(), from demux_audio.c
static void demux_aac_seek(demuxer_t *demuxer, float rel_seek_secs, float audio_delay, int flags)
{
aac_priv_t *priv = (aac_priv_t *) demuxer->priv;
demux_stream_t *d_audio=demuxer->audio;
sh_audio_t *sh_audio=d_audio->sh;
float time;
ds_free_packs(d_audio);
time = (flags & SEEK_ABSOLUTE) ? rel_seek_secs - priv->last_pts : rel_seek_secs;
if(time < 0)
{
stream_seek(demuxer->stream, demuxer->movi_start);
time = priv->last_pts + time;
priv->last_pts = 0;
}
if(time > 0)
{
int len, nf, srate, num;
nf = time * sh_audio->samplerate/1024;
while(nf > 0)
{
if(stream_read(demuxer->stream,priv->buf, 8) < 8)
break;
len = aac_parse_frame(priv->buf, &srate, &num);
if(len <= 0)
{
stream_skip(demuxer->stream, -7);
continue;
}
stream_skip(demuxer->stream, len - 8);
priv->last_pts += (float) (num*1024.0/srate);
nf -= num;
}
}
}
const demuxer_desc_t demuxer_desc_aac = {
"AAC demuxer",
"aac",
"AAC",
"Nico Sabbi",
"Raw AAC files ",
DEMUXER_TYPE_AAC,
0, // unsafe autodetect
demux_aac_probe,
demux_aac_fill_buffer,
demux_aac_open,
demux_close_aac,
demux_aac_seek,
NULL
};
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