[FFmpeg-cvslog] mpegts: adjustable minimum PES payload
Jindřich Makovička
git at videolan.org
Thu Dec 29 02:01:05 CET 2011
ffmpeg | branch: master | Jindřich Makovička <makovick at gmail.com> | Mon Dec 19 20:15:21 2011 +0100| [891ce00c8ddad096cc26d7aa55b4f1bc26a1f124] | committer: Anton Khirnov
mpegts: adjustable minimum PES payload
With the current default PES packet size, and very small audio bitrates,
audio packet duration gets too long. For players, which wait for a whole
audio packet (or more) it takes a very long time to start playing sound.
For 24kbps audio, one PES packet is about 1 second long. On Motorola STBs,
we observe about 3 second delay before the playback starts with the
default setting.
Signed-off-by: Anton Khirnov <anton at khirnov.net>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=891ce00c8ddad096cc26d7aa55b4f1bc26a1f124
---
libavformat/mpegtsenc.c | 35 ++++++++++++++++++++++++++---------
1 files changed, 26 insertions(+), 9 deletions(-)
diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
index 48b1617..90f2232 100644
--- a/libavformat/mpegtsenc.c
+++ b/libavformat/mpegtsenc.c
@@ -68,6 +68,7 @@ typedef struct MpegTSWrite {
int tsid;
int64_t first_pcr;
int mux_rate; ///< set to 1 when VBR
+ int pes_payload_size;
int transport_stream_id;
int original_network_id;
@@ -77,6 +78,10 @@ typedef struct MpegTSWrite {
int start_pid;
} MpegTSWrite;
+/* a PES packet header is generated every DEFAULT_PES_HEADER_FREQ packets */
+#define DEFAULT_PES_HEADER_FREQ 16
+#define DEFAULT_PES_PAYLOAD_SIZE ((DEFAULT_PES_HEADER_FREQ - 1) * 184 + 170)
+
static const AVOption options[] = {
{ "mpegts_transport_stream_id", "Set transport_stream_id field.",
offsetof(MpegTSWrite, transport_stream_id), AV_OPT_TYPE_INT, {.dbl = 0x0001 }, 0x0001, 0xffff, AV_OPT_FLAG_ENCODING_PARAM},
@@ -89,6 +94,8 @@ static const AVOption options[] = {
{ "mpegts_start_pid", "Set the first pid.",
offsetof(MpegTSWrite, start_pid), AV_OPT_TYPE_INT, {.dbl = 0x0100 }, 0x0100, 0x0f00, AV_OPT_FLAG_ENCODING_PARAM},
{ "muxrate", NULL, offsetof(MpegTSWrite, mux_rate), AV_OPT_TYPE_INT, {1}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
+ { "pes_payload_size", "Minimum PES packet payload in bytes",
+ offsetof(MpegTSWrite, pes_payload_size), AV_OPT_TYPE_INT, {DEFAULT_PES_PAYLOAD_SIZE}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
{ NULL },
};
@@ -188,10 +195,6 @@ static int mpegts_write_section1(MpegTSSection *s, int tid, int id,
#define DEFAULT_PROVIDER_NAME "Libav"
#define DEFAULT_SERVICE_NAME "Service01"
-/* a PES packet header is generated every DEFAULT_PES_HEADER_FREQ packets */
-#define DEFAULT_PES_HEADER_FREQ 16
-#define DEFAULT_PES_PAYLOAD_SIZE ((DEFAULT_PES_HEADER_FREQ - 1) * 184 + 170)
-
/* we retransmit the SI info at this rate */
#define SDT_RETRANS_TIME 500
#define PAT_RETRANS_TIME 100
@@ -206,7 +209,7 @@ typedef struct MpegTSWriteStream {
int64_t payload_pts;
int64_t payload_dts;
int payload_flags;
- uint8_t payload[DEFAULT_PES_PAYLOAD_SIZE];
+ uint8_t *payload;
ADTSContext *adts;
} MpegTSWriteStream;
@@ -453,6 +456,9 @@ static int mpegts_write_header(AVFormatContext *s)
const char *provider_name;
int *pids;
+ // round up to a whole number of TS packets
+ ts->pes_payload_size = (ts->pes_payload_size + 14 + 183) / 184 * 184 - 14;
+
ts->tsid = ts->transport_stream_id;
ts->onid = ts->original_network_id;
/* allocate a single DVB service */
@@ -489,6 +495,9 @@ static int mpegts_write_header(AVFormatContext *s)
if (!ts_st)
goto fail;
st->priv_data = ts_st;
+ ts_st->payload = av_mallocz(ts->pes_payload_size);
+ if (!ts_st->payload)
+ goto fail;
ts_st->service = service;
/* MPEG pid values < 16 are reserved. Applications which set st->id in
* this range are assigned a calculated pid. */
@@ -524,10 +533,10 @@ static int mpegts_write_header(AVFormatContext *s)
st->codec->extradata_size > 0) {
ts_st->adts = av_mallocz(sizeof(*ts_st->adts));
if (!ts_st->adts)
- return AVERROR(ENOMEM);
+ goto fail;
if (ff_adts_decode_extradata(s, ts_st->adts, st->codec->extradata,
st->codec->extradata_size) < 0)
- return -1;
+ goto fail;
}
}
@@ -595,7 +604,13 @@ static int mpegts_write_header(AVFormatContext *s)
fail:
av_free(pids);
for(i = 0;i < s->nb_streams; i++) {
+ MpegTSWriteStream *ts_st;
st = s->streams[i];
+ ts_st = st->priv_data;
+ if (ts_st) {
+ av_freep(&ts_st->payload);
+ av_freep(&ts_st->adts);
+ }
av_freep(&st->priv_data);
}
return -1;
@@ -924,6 +939,7 @@ static int mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)
int size = pkt->size;
uint8_t *buf= pkt->data;
uint8_t *data= NULL;
+ MpegTSWrite *ts = s->priv_data;
MpegTSWriteStream *ts_st = st->priv_data;
const uint64_t delay = av_rescale(s->max_delay, 90000, AV_TIME_BASE)*2;
int64_t dts = AV_NOPTS_VALUE, pts = AV_NOPTS_VALUE;
@@ -1006,14 +1022,14 @@ static int mpegts_write_packet(AVFormatContext *s, AVPacket *pkt)
return 0;
}
- if (ts_st->payload_size + size > DEFAULT_PES_PAYLOAD_SIZE) {
+ if (ts_st->payload_size + size > ts->pes_payload_size) {
if (ts_st->payload_size) {
mpegts_write_pes(s, st, ts_st->payload, ts_st->payload_size,
ts_st->payload_pts, ts_st->payload_dts,
ts_st->payload_flags & AV_PKT_FLAG_KEY);
ts_st->payload_size = 0;
}
- if (size > DEFAULT_PES_PAYLOAD_SIZE) {
+ if (size > ts->pes_payload_size) {
mpegts_write_pes(s, st, buf, size, pts, dts,
pkt->flags & AV_PKT_FLAG_KEY);
av_free(data);
@@ -1052,6 +1068,7 @@ static int mpegts_write_end(AVFormatContext *s)
ts_st->payload_pts, ts_st->payload_dts,
ts_st->payload_flags & AV_PKT_FLAG_KEY);
}
+ av_freep(&ts_st->payload);
av_freep(&ts_st->adts);
}
avio_flush(s->pb);
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