RepoMirrors/mpv
1
0
Fork 0
mirror of https://github.com/mpv-player/mpv synced 2025-02-21 07:16:56 +00:00
Code Issues Releases Wiki Activity

when muxing mpeg audio streams analyze the first 32 KB of data to obtain the most likely correct layer, otherwise every misdetection during parse_audio() will lead to wrong timestamps and loss of synchrony

Browse Source 
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@18249 b3059339-0415-0410-9bf9-f77b7e298cf2
This commit is contained in:
nicodvb 2006-04-24 14:04:10 +00:00
parent 21dc86a871
commit ac1506c8b3
1 changed files with 51 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
libmpdemux/muxer_mpeg.c
View File

@ -169,6 +169,7 @@ typedef struct {
int frames;
int last_frame_rest; //the rest of the previous frame
int is_ready;
int mpa_layer;
} muxer_headers_t;
#define PULLDOWN32 1
@ -2040,6 +2041,38 @@ static int add_frame(muxer_headers_t *spriv, uint64_t idur, uint8_t *ptr, int le
return idx;
}
static int analyze_mpa(muxer_stream_t *s)
{
int i = 0, len, max, chans, srate, spf, layer;
int score[4] = {0, 0, 0, 0};
while(i < s->b_buffer_len + 3)
{
if(s->b_buffer[i] == 0xFF && ((s->b_buffer[i+1] & 0xE0) == 0xE0))
{
len = mp_get_mp3_header(&(s->b_buffer[i]), &chans, &srate, &spf, &layer, NULL);
if(len > 0 && (srate == s->wf->nSamplesPerSec) && (i + len <= s->b_buffer_len))
{
score[layer]++;
i += len;
}
}
i++;
}
max = 0;
layer = 2;
for(i = 1; i <= 3; i++)
{
if(score[i] >= max)
{
max = score[i];
layer = i;
}
}
return layer; //actual layer with the highest score
}
extern int aac_parse_frame(uint8_t *buf, int *srate, int *num);
@ -2071,7 +2104,8 @@ static int parse_audio(muxer_stream_t *s, int finalize, unsigned int *nf, double
if(s->b_buffer[i] == 0xFF && ((s->b_buffer[i+1] & 0xE0) == 0xE0))
{
len = mp_get_mp3_header(&(s->b_buffer[i]), &chans, &srate, &spf, &layer, NULL);
if(len > 0 && (srate == s->wf->nSamplesPerSec) && (i + len <= s->b_buffer_len))
if(len > 0 && (srate == s->wf->nSamplesPerSec) && (i + len <= s->b_buffer_len)
&& layer == spriv->mpa_layer)
{
dur = (double) spf / (double) srate;
idur = (27000000ULL * spf) / srate;
@ -2200,6 +2234,7 @@ static void fix_parameters(muxer_stream_t *stream)
if(stream->type == MUXER_TYPE_AUDIO)
{
spriv->is_ready = 1;
spriv->max_buffer_size = 4*1024;
if(stream->wf->wFormatTag == AUDIO_A52)
{
@ -2213,6 +2248,8 @@ static void fix_parameters(muxer_stream_t *stream)
{
priv->use_psm = 1;
}
else if(stream->wf->wFormatTag == AUDIO_MP2 || stream->wf->wFormatTag == AUDIO_MP3)
spriv->is_ready = 0;
}
else //video
{
@ -2294,8 +2331,6 @@ static void mpegfile_write_chunk(muxer_stream_t *s,size_t len,unsigned int flags
spriv->type = 0;
stream_format = s->wf->wFormatTag;
if(! spriv->vframes)
mp_msg(MSGT_MUXER, MSGL_INFO, "AINIT: %.3lf\r\n", (double) spriv->last_pts/27000000.0f);
if(s->b_buffer_size - s->b_buffer_len < len)
{
s->b_buffer = realloc(s->b_buffer, len + s->b_buffer_len);
@ -2311,9 +2346,22 @@ static void mpegfile_write_chunk(muxer_stream_t *s,size_t len,unsigned int flags
memcpy(&(s->b_buffer[s->b_buffer_ptr + s->b_buffer_len]), s->buffer, len);
s->b_buffer_len += len;
if(!spriv->is_ready)
{
if(s->b_buffer_len >= 32*1024)
{
spriv->mpa_layer = analyze_mpa(s);
spriv->is_ready = 1;
}
}
else
{
parse_audio(s, 0, &nf, &fake_timer, priv->init_adelay, priv->drop);
spriv->vframes += nf;
sz = max(len, 2 * priv->packet_size);
if(! spriv->vframes)
mp_msg(MSGT_MUXER, MSGL_INFO, "AINIT: %.3lf\r\n", (double) spriv->last_pts/27000000.0f);
}
}