[FFmpeg-cvslog] avconv: buffer the packets written while the muxer is not initialized
Anton Khirnov
git at videolan.org
Sat Oct 8 12:39:19 EEST 2016
ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Mon May 23 10:48:26 2016 +0200| [398f015f077c6a2406deffd9e37ff34b9c7bb3bc] | committer: Anton Khirnov
avconv: buffer the packets written while the muxer is not initialized
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=398f015f077c6a2406deffd9e37ff34b9c7bb3bc
---
avconv.c | 76 +++++++++++++++++++++++++++++++++++++++++++--------------
avconv.h | 7 ++++++
avconv_opt.c | 11 +++++++++
doc/avconv.texi | 9 +++++++
4 files changed, 85 insertions(+), 18 deletions(-)
diff --git a/avconv.c b/avconv.c
index 6c100ff..6401760 100644
--- a/avconv.c
+++ b/avconv.c
@@ -192,6 +192,13 @@ static void avconv_cleanup(int ret)
avcodec_free_context(&ost->enc_ctx);
+ while (av_fifo_size(ost->muxing_queue)) {
+ AVPacket pkt;
+ av_fifo_generic_read(ost->muxing_queue, &pkt, sizeof(pkt), NULL);
+ av_packet_unref(&pkt);
+ }
+ av_fifo_free(ost->muxing_queue);
+
av_freep(&output_streams[i]);
}
for (i = 0; i < nb_input_files; i++) {
@@ -255,11 +262,33 @@ static void abort_codec_experimental(AVCodec *c, int encoder)
exit_program(1);
}
-static void write_packet(AVFormatContext *s, AVPacket *pkt, OutputStream *ost)
+static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost)
{
+ AVFormatContext *s = of->ctx;
AVStream *st = ost->st;
int ret;
+ if (!of->header_written) {
+ AVPacket tmp_pkt;
+ /* the muxer is not initialized yet, buffer the packet */
+ if (!av_fifo_space(ost->muxing_queue)) {
+ int new_size = FFMIN(2 * av_fifo_size(ost->muxing_queue),
+ ost->max_muxing_queue_size);
+ if (new_size <= av_fifo_size(ost->muxing_queue)) {
+ av_log(NULL, AV_LOG_ERROR,
+ "Too many packets buffered for output stream %d:%d.\n",
+ ost->file_index, ost->st->index);
+ exit_program(1);
+ }
+ ret = av_fifo_realloc2(ost->muxing_queue, new_size);
+ if (ret < 0)
+ exit_program(1);
+ }
+ av_packet_move_ref(&tmp_pkt, pkt);
+ av_fifo_generic_write(ost->muxing_queue, &tmp_pkt, sizeof(tmp_pkt), NULL);
+ return;
+ }
+
/*
* Audio encoders may split the packets -- #frames in != #packets out.
* But there is no reordering, so we can limit the number of output packets
@@ -315,7 +344,7 @@ static void write_packet(AVFormatContext *s, AVPacket *pkt, OutputStream *ost)
}
}
-static void output_packet(AVFormatContext *s, AVPacket *pkt, OutputStream *ost)
+static void output_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost)
{
int ret = 0;
@@ -345,10 +374,10 @@ static void output_packet(AVFormatContext *s, AVPacket *pkt, OutputStream *ost)
goto finish;
idx++;
} else
- write_packet(s, pkt, ost);
+ write_packet(of, pkt, ost);
}
} else
- write_packet(s, pkt, ost);
+ write_packet(of, pkt, ost);
finish:
if (ret < 0 && ret != AVERROR_EOF) {
@@ -371,7 +400,7 @@ static int check_recording_time(OutputStream *ost)
return 1;
}
-static void do_audio_out(AVFormatContext *s, OutputStream *ost,
+static void do_audio_out(OutputFile *of, OutputStream *ost,
AVFrame *frame)
{
AVCodecContext *enc = ost->enc_ctx;
@@ -401,7 +430,7 @@ static void do_audio_out(AVFormatContext *s, OutputStream *ost,
goto error;
av_packet_rescale_ts(&pkt, enc->time_base, ost->st->time_base);
- output_packet(s, &pkt, ost);
+ output_packet(of, &pkt, ost);
}
return;
@@ -410,7 +439,7 @@ error:
exit_program(1);
}
-static void do_subtitle_out(AVFormatContext *s,
+static void do_subtitle_out(OutputFile *of,
OutputStream *ost,
InputStream *ist,
AVSubtitle *sub,
@@ -475,11 +504,11 @@ static void do_subtitle_out(AVFormatContext *s,
else
pkt.pts += 90 * sub->end_display_time;
}
- output_packet(s, &pkt, ost);
+ output_packet(of, &pkt, ost);
}
}
-static void do_video_out(AVFormatContext *s,
+static void do_video_out(OutputFile *of,
OutputStream *ost,
AVFrame *in_picture,
int *frame_size)
@@ -492,8 +521,8 @@ static void do_video_out(AVFormatContext *s,
format_video_sync = video_sync_method;
if (format_video_sync == VSYNC_AUTO)
- format_video_sync = (s->oformat->flags & AVFMT_NOTIMESTAMPS) ? VSYNC_PASSTHROUGH :
- (s->oformat->flags & AVFMT_VARIABLE_FPS) ? VSYNC_VFR : VSYNC_CFR;
+ format_video_sync = (of->ctx->oformat->flags & AVFMT_NOTIMESTAMPS) ? VSYNC_PASSTHROUGH :
+ (of->ctx->oformat->flags & AVFMT_VARIABLE_FPS) ? VSYNC_VFR : VSYNC_CFR;
if (format_video_sync != VSYNC_PASSTHROUGH &&
ost->frame_number &&
in_picture->pts != AV_NOPTS_VALUE &&
@@ -552,7 +581,7 @@ static void do_video_out(AVFormatContext *s,
goto error;
av_packet_rescale_ts(&pkt, enc->time_base, ost->st->time_base);
- output_packet(s, &pkt, ost);
+ output_packet(of, &pkt, ost);
*frame_size = pkt.size;
/* if two pass, output log */
@@ -662,12 +691,12 @@ static int poll_filter(OutputStream *ost)
if (!ost->frame_aspect_ratio)
ost->enc_ctx->sample_aspect_ratio = filtered_frame->sample_aspect_ratio;
- do_video_out(of->ctx, ost, filtered_frame, &frame_size);
+ do_video_out(of, ost, filtered_frame, &frame_size);
if (vstats_filename && frame_size)
do_video_stats(ost, frame_size);
break;
case AVMEDIA_TYPE_AUDIO:
- do_audio_out(of->ctx, ost, filtered_frame);
+ do_audio_out(of, ost, filtered_frame);
break;
default:
// TODO support subtitle filters
@@ -975,7 +1004,7 @@ static void flush_encoders(void)
for (i = 0; i < nb_output_streams; i++) {
OutputStream *ost = output_streams[i];
AVCodecContext *enc = ost->enc_ctx;
- AVFormatContext *os = output_files[ost->file_index]->ctx;
+ OutputFile *of = output_files[ost->file_index];
int stop_encoding = 0;
if (!ost->encoding_needed)
@@ -1022,7 +1051,7 @@ static void flush_encoders(void)
break;
}
av_packet_rescale_ts(&pkt, enc->time_base, ost->st->time_base);
- output_packet(os, &pkt, ost);
+ output_packet(of, &pkt, ost);
}
if (stop_encoding)
@@ -1115,7 +1144,7 @@ static void do_streamcopy(InputStream *ist, OutputStream *ost, const AVPacket *p
opkt.size = pkt->size;
}
- output_packet(of->ctx, &opkt, ost);
+ output_packet(of, &opkt, ost);
}
// This does not quite work like avcodec_decode_audio4/avcodec_decode_video2.
@@ -1353,7 +1382,7 @@ static int transcode_subtitles(InputStream *ist, AVPacket *pkt, int *got_output)
if (!check_output_constraints(ist, ost) || !ost->encoding_needed)
continue;
- do_subtitle_out(output_files[ost->file_index]->ctx, ost, ist, &subtitle, pkt->pts);
+ do_subtitle_out(output_files[ost->file_index], ost, ist, &subtitle, pkt->pts);
}
avsubtitle_free(&subtitle);
@@ -1657,6 +1686,17 @@ static int check_init_output_file(OutputFile *of, int file_index)
if (want_sdp)
print_sdp();
+ /* flush the muxing queues */
+ for (i = 0; i < of->ctx->nb_streams; i++) {
+ OutputStream *ost = output_streams[of->ost_index + i];
+
+ while (av_fifo_size(ost->muxing_queue)) {
+ AVPacket pkt;
+ av_fifo_generic_read(ost->muxing_queue, &pkt, sizeof(pkt), NULL);
+ write_packet(of, &pkt, ost);
+ }
+ }
+
return 0;
}
diff --git a/avconv.h b/avconv.h
index bc3b6c3..60729c3 100644
--- a/avconv.h
+++ b/avconv.h
@@ -190,6 +190,8 @@ typedef struct OptionsContext {
int nb_pass;
SpecifierOpt *passlogfiles;
int nb_passlogfiles;
+ SpecifierOpt *max_muxing_queue_size;
+ int nb_max_muxing_queue_size;
} OptionsContext;
typedef struct InputFilter {
@@ -391,6 +393,11 @@ typedef struct OutputStream {
/* packet quality factor */
int quality;
+
+ int max_muxing_queue_size;
+
+ /* the packets are buffered here until the muxer is ready to be initialized */
+ AVFifoBuffer *muxing_queue;
} OutputStream;
typedef struct OutputFile {
diff --git a/avconv_opt.c b/avconv_opt.c
index 2a4f71a..a1729c3 100644
--- a/avconv_opt.c
+++ b/avconv_opt.c
@@ -1073,6 +1073,10 @@ static OutputStream *new_output_stream(OptionsContext *o, AVFormatContext *oc, e
ost->enc_ctx->global_quality = FF_QP2LAMBDA * qscale;
}
+ ost->max_muxing_queue_size = 128;
+ MATCH_PER_STREAM_OPT(max_muxing_queue_size, i, ost->max_muxing_queue_size, oc, st);
+ ost->max_muxing_queue_size *= sizeof(AVPacket);
+
if (oc->oformat->flags & AVFMT_GLOBALHEADER)
ost->enc_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
@@ -1083,6 +1087,10 @@ static OutputStream *new_output_stream(OptionsContext *o, AVFormatContext *oc, e
ost->pix_fmts[0] = ost->pix_fmts[1] = AV_PIX_FMT_NONE;
ost->last_mux_dts = AV_NOPTS_VALUE;
+ ost->muxing_queue = av_fifo_alloc(8 * sizeof(AVPacket));
+ if (!ost->muxing_queue)
+ exit_program(1);
+
return ost;
}
@@ -2648,6 +2656,9 @@ const OptionDef options[] = {
{ "bsf", HAS_ARG | OPT_STRING | OPT_SPEC | OPT_EXPERT | OPT_OUTPUT, { .off = OFFSET(bitstream_filters) },
"A comma-separated list of bitstream filters", "bitstream_filters" },
+ { "max_muxing_queue_size", HAS_ARG | OPT_INT | OPT_SPEC | OPT_EXPERT | OPT_OUTPUT, { .off = OFFSET(max_muxing_queue_size) },
+ "maximum number of packets that can be buffered while waiting for all streams to initialize", "packets" },
+
/* data codec support */
{ "dcodec", HAS_ARG | OPT_DATA | OPT_PERFILE | OPT_EXPERT | OPT_INPUT | OPT_OUTPUT, { .func_arg = opt_data_codec },
"force data codec ('copy' to copy stream)", "codec" },
diff --git a/doc/avconv.texi b/doc/avconv.texi
index cdfef55..9f2f295 100644
--- a/doc/avconv.texi
+++ b/doc/avconv.texi
@@ -956,6 +956,15 @@ This option enables or disables accurate seeking in input files with the
transcoding. Use @option{-noaccurate_seek} to disable it, which may be useful
e.g. when copying some streams and transcoding the others.
+ at item -max_muxing_queue_size @var{packets} (@emph{output,per-stream})
+When transcoding audio and/or video streams, avconv will not begin writing into
+the output until it has one packet for each such stream. While waiting for that
+to happen, packets for other streams are buffered. This option sets the size of
+this buffer, in packets, for the matching output stream.
+
+The default value of this option should be high enough for most uses, so only
+touch this option if you are sure that you need it.
+
@end table
@c man end OPTIONS
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