[Ffmpeg-devel] [PATCH] sync output stream against any input stream (extension of map)
Wolfram Gloger
wmglo
Wed May 25 17:49:36 CEST 2005
Hi,
Until sometime last year, audio streams were always the "master" in
ffmpeg when it came to synchronization.
Today, there is no master anymore and every output stream is "only"
synched against its corresponding input.
This is basically ok, because "-async" was introduced at the same time
and works quite well to compensate drift in audio streams. However,
sometimes you can't or don't want to use "-async", eg. with "-acodec
copy". Then, it may still be acceptable to drop/dup video frames and
you want to synchronize the video against a particular audio stream.
The opposite is also conceivable: you don't want to mess with the
video frame order at all ("-vsync 0" or "-vcodec copy") but still want
to use "-async 50", for example.
In those cases I think the appended patch is useful, and I think it is
_necessary_ for output formats without timestams. There are simply
two additional (optional) arguments to "-map" specifying the input
stream to sync against.
Regards,
Wolfram.
--- ffmpeg-wg/ffmpeg.c.orig Mon May 23 09:53:35 2005
+++ ffmpeg-wg/ffmpeg.c Wed May 25 17:28:19 2005
@@ -52,6 +52,8 @@
typedef struct AVStreamMap {
int file_index;
int stream_index;
+ int sync_file_index;
+ int sync_stream_index;
} AVStreamMap;
/** select an input file for an output file */
@@ -277,6 +279,8 @@
#define DEFAULT_PASS_LOGFILENAME "ffmpeg2pass"
+struct AVInputStream;
+
typedef struct AVOutputStream {
int file_index; /* file index */
int index; /* stream index in the output file */
@@ -286,7 +290,8 @@
int frame_number;
/* input pts and corresponding output pts
for A/V sync */
- double sync_ipts; /* dts from the AVPacket of the demuxer in second units */
+ //double sync_ipts; /* dts from the AVPacket of the demuxer in second units */
+ struct AVInputStream *sync_ist; /* input stream to sync against */
int64_t sync_opts; /* output frame counter, could be changed to some true timestamp */ //FIXME look at frame_number
/* video only */
int video_resample; /* video_resample and video_crop are mutually exclusive */
@@ -456,6 +461,13 @@
return 0;
}
+static double
+get_sync_ipts(const AVOutputStream *ost)
+{
+ const AVInputStream *ist = ost->sync_ist;
+ return (double)(ist->pts + input_files_ts_offset[ist->file_index] - start_time)/AV_TIME_BASE;
+}
+
#define MAX_AUDIO_PACKET_SIZE (128 * 1024)
static void do_audio_out(AVFormatContext *s,
@@ -480,7 +492,7 @@
return; /* Should signal an error ! */
if(audio_sync_method){
- double delta = ost->sync_ipts * enc->sample_rate - ost->sync_opts
+ double delta = get_sync_ipts(ost) * enc->sample_rate - ost->sync_opts
- fifo_size(&ost->fifo, ost->fifo.rptr)/(ost->st->codec.channels * 2);
double idelta= delta*ist->st->codec.sample_rate / enc->sample_rate;
int byte_delta= ((int)idelta)*2*ist->st->codec.channels;
@@ -518,12 +530,12 @@
assert(ost->audio_resample);
if(verbose > 2)
fprintf(stderr, "compensating audio timestamp drift:%f compensation:%d in:%d\n", delta, comp, enc->sample_rate);
-// fprintf(stderr, "drift:%f len:%d opts:%lld ipts:%lld fifo:%d\n", delta, -1, ost->sync_opts, (int64_t)(ost->sync_ipts * enc->sample_rate), fifo_size(&ost->fifo, ost->fifo.rptr)/(ost->st->codec.channels * 2));
+// fprintf(stderr, "drift:%f len:%d opts:%lld ipts:%lld fifo:%d\n", delta, -1, ost->sync_opts, (int64_t)(get_sync_ipts(ost) * enc->sample_rate), fifo_size(&ost->fifo, ost->fifo.rptr)/(ost->st->codec.channels * 2));
av_resample_compensate(*(struct AVResampleContext**)ost->resample, comp, enc->sample_rate);
}
}
}else
- ost->sync_opts= lrintf(ost->sync_ipts * enc->sample_rate)
+ ost->sync_opts= lrintf(get_sync_ipts(ost) * enc->sample_rate)
- fifo_size(&ost->fifo, ost->fifo.rptr)/(ost->st->codec.channels * 2); //FIXME wrong
if (ost->audio_resample) {
@@ -709,7 +721,7 @@
if(video_sync_method){
double vdelta;
- vdelta = ost->sync_ipts / av_q2d(enc->time_base) - ost->sync_opts;
+ vdelta = get_sync_ipts(ost) / av_q2d(enc->time_base) - ost->sync_opts;
//FIXME set to 0.5 after we fix some dts/pts bugs like in avidec.c
if (vdelta < -1.1)
nb_frames = 0;
@@ -726,7 +738,7 @@
fprintf(stderr, "*** %d dup!\n", nb_frames-1);
}
}else
- ost->sync_opts= lrintf(ost->sync_ipts / av_q2d(enc->time_base));
+ ost->sync_opts= lrintf(get_sync_ipts(ost) / av_q2d(enc->time_base));
nb_frames= FFMIN(nb_frames, max_frames[CODEC_TYPE_VIDEO] - ost->frame_number);
if (nb_frames <= 0)
@@ -1267,7 +1279,7 @@
((double)ost->st->pts.val * ost->st->time_base.num / ost->st->time_base.den));
#endif
/* set the input output pts pairs */
- ost->sync_ipts = (double)(ist->pts + input_files_ts_offset[ist->file_index] - start_time)/ AV_TIME_BASE;
+ //ost->sync_ipts = (double)(ist->pts + input_files_ts_offset[ist->file_index] - start_time)/ AV_TIME_BASE;
if (ost->encoding_needed) {
switch(ost->st->codec.codec_type) {
@@ -1460,6 +1472,13 @@
fprintf(stderr,"Could not find input stream #%d.%d\n", fi, si);
exit(1);
}
+ fi = stream_maps[i].sync_file_index;
+ si = stream_maps[i].sync_stream_index;
+ if (fi < 0 || fi > nb_input_files - 1 ||
+ si < 0 || si > file_table[fi].nb_streams - 1) {
+ fprintf(stderr,"Could not find sync stream #%d.%d\n", fi, si);
+ exit(1);
+ }
}
ost_table = av_mallocz(sizeof(AVOutputStream *) * nb_ostreams);
@@ -1524,6 +1543,9 @@
}
ist = ist_table[ost->source_index];
ist->discard = 0;
+ ost->sync_ist = (nb_stream_maps > 0) ?
+ ist_table[file_table[stream_maps[n-1].sync_file_index].ist_index +
+ stream_maps[n-1].sync_stream_index] : ist;
}
}
@@ -1728,11 +1750,16 @@
fprintf(stderr, "Stream mapping:\n");
for(i=0;i<nb_ostreams;i++) {
ost = ost_table[i];
- fprintf(stderr, " Stream #%d.%d -> #%d.%d\n",
+ fprintf(stderr, " Stream #%d.%d -> #%d.%d",
ist_table[ost->source_index]->file_index,
ist_table[ost->source_index]->index,
ost->file_index,
ost->index);
+ if (ost->sync_ist != ist_table[ost->source_index])
+ fprintf(stderr, " [sync #%d.%d]",
+ ost->sync_ist->file_index,
+ ost->sync_ist->index);
+ fprintf(stderr, "\n");
}
}
@@ -2816,6 +2843,16 @@
p++;
m->stream_index = strtol(p, (char **)&p, 0);
+ if (*p) {
+ p++;
+ m->sync_file_index = strtol(p, (char **)&p, 0);
+ if (*p)
+ p++;
+ m->sync_stream_index = strtol(p, (char **)&p, 0);
+ } else {
+ m->sync_file_index = m->file_index;
+ m->sync_stream_index = m->stream_index;
+ }
}
static void opt_map_meta_data(const char *arg)
@@ -3929,7 +3966,7 @@
{ "img", HAS_ARG, {(void*)opt_image_format}, "force image format", "img_fmt" },
{ "i", HAS_ARG, {(void*)opt_input_file}, "input file name", "filename" },
{ "y", OPT_BOOL, {(void*)&file_overwrite}, "overwrite output files" },
- { "map", HAS_ARG | OPT_EXPERT, {(void*)opt_map}, "set input stream mapping", "file:stream" },
+ { "map", HAS_ARG | OPT_EXPERT, {(void*)opt_map}, "set input stream mapping", "file:stream[:syncfile:syncstream]" },
{ "map_meta_data", HAS_ARG | OPT_EXPERT, {(void*)opt_map_meta_data}, "set meta data information of outfile from infile", "outfile:infile" },
{ "t", HAS_ARG, {(void*)opt_recording_time}, "set the recording time", "duration" },
{ "fs", HAS_ARG | OPT_INT, {(void*)&limit_filesize}, "set the limit file size", "limit_size" }, //
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