On Wed, 21 Oct 2020, lance.lmw...@gmail.com wrote:
From: Limin Wang <lance.lmw...@gmail.com>
avio_tell() failed to get corrected data size in some condition.
Please explain. E.g. avio_tell() fails to get the amount of
data written so far when the underlying IO context is flushed to segments.
Please test with below command:
$ ./ffmpeg -f lavfi -i testsrc=duration=100:size=vga -c:v libx264 -x264opts \
nal-hrd=cbr:force-cfr=1 -b:v 500k -minrate 500k -maxrate 500k -bufsize 500k \
-f hls -hls_time 10 -hls_ts_options "muxrate=2000000" test%d.ts
$ du -h test*.ts
Before:
2.4M test00.ts
4.8M test11.ts
7.2M test22.ts
9.6M test33.ts
12M test44.ts
15M test55.ts
17M test66.ts
20M test77.ts
22M test88.ts
24M test99.ts
After apply the patch:
2.4M test00.ts
2.4M test11.ts
2.4M test22.ts
2.4M test33.ts
2.4M test44.ts
2.4M test55.ts
2.4M test66.ts
2.4M test77.ts
2.4M test88.ts
2.4M test99.ts
4.0K test%d.ts
Signed-off-by: Limin Wang <lance.lmw...@gmail.com>
---
libavformat/mpegtsenc.c | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/libavformat/mpegtsenc.c b/libavformat/mpegtsenc.c
index afdadda..e05d0ce 100644
--- a/libavformat/mpegtsenc.c
+++ b/libavformat/mpegtsenc.c
@@ -84,6 +84,7 @@ typedef struct MpegTSWrite {
int64_t next_pcr;
int mux_rate; ///< set to 1 when VBR
int pes_payload_size;
+ int64_t total_size;
int transport_stream_id;
int original_network_id;
@@ -830,9 +831,9 @@ invalid:
return 0;
}
-static int64_t get_pcr(const MpegTSWrite *ts, AVIOContext *pb)
+static int64_t get_pcr(const MpegTSWrite *ts)
{
- return av_rescale(avio_tell(pb) + 11, 8 * PCR_TIME_BASE, ts->mux_rate) +
+ return av_rescale(ts->total_size + 11, 8 * PCR_TIME_BASE, ts->mux_rate) +
ts->first_pcr;
}
@@ -840,13 +841,15 @@ static void write_packet(AVFormatContext *s, const
uint8_t *packet)
{
MpegTSWrite *ts = s->priv_data;
if (ts->m2ts_mode) {
- int64_t pcr = get_pcr(s->priv_data, s->pb);
+ int64_t pcr = get_pcr(s->priv_data);
uint32_t tp_extra_header = pcr % 0x3fffffff;
tp_extra_header = AV_RB32(&tp_extra_header);
avio_write(s->pb, (unsigned char *) &tp_extra_header,
sizeof(tp_extra_header));
+ ts->total_size += sizeof(tp_extra_header);
The PCR of M2TS should not be affected by the extra header, so please
remove this addition. Also see my last comment.
}
avio_write(s->pb, packet, TS_PACKET_SIZE);
+ ts->total_size += TS_PACKET_SIZE;
}
static void section_write_packet(MpegTSSection *s, const uint8_t *packet)
@@ -987,6 +990,7 @@ static int mpegts_init(AVFormatContext *s)
}
}
+ ts->total_size = 0;
Unneeded initialization, please remove.
if (s->max_delay < 0) /* Not set by the caller */
s->max_delay = 0;
@@ -1228,7 +1232,7 @@ static void mpegts_insert_pcr_only(AVFormatContext *s,
AVStream *st)
}
/* PCR coded into 6 bytes */
- q += write_pcr_bits(q, get_pcr(ts, s->pb));
+ q += write_pcr_bits(q, get_pcr(ts));
/* stuffing bytes */
memset(q, 0xFF, TS_PACKET_SIZE - (q - buf));
@@ -1315,7 +1319,7 @@ static void mpegts_write_pes(AVFormatContext *s, AVStream
*st,
while (payload_size > 0) {
int64_t pcr = AV_NOPTS_VALUE;
if (ts->mux_rate > 1)
- pcr = get_pcr(ts, s->pb);
+ pcr = get_pcr(ts);
else if (dts != AV_NOPTS_VALUE)
pcr = (dts - delay) * 300;
@@ -1326,7 +1330,7 @@ static void mpegts_write_pes(AVFormatContext *s, AVStream
*st,
write_pcr = 0;
if (ts->mux_rate > 1) {
/* Send PCR packets for all PCR streams if needed */
- pcr = get_pcr(ts, s->pb);
+ pcr = get_pcr(ts);
if (pcr >= ts->next_pcr) {
int64_t next_pcr = INT64_MAX;
for (int i = 0; i < s->nb_streams; i++) {
@@ -1340,7 +1344,7 @@ static void mpegts_write_pes(AVFormatContext *s, AVStream
*st,
ts_st2->last_pcr = FFMAX(pcr - ts_st2->pcr_period,
ts_st2->last_pcr + ts_st2->pcr_period);
if (st2 != st) {
mpegts_insert_pcr_only(s, st2);
- pcr = get_pcr(ts, s->pb);
+ pcr = get_pcr(ts);
} else {
write_pcr = 1;
}
@@ -1983,7 +1987,7 @@ static void mpegts_write_flush(AVFormatContext *s)
}
if (ts->m2ts_mode) {
- int packets = (avio_tell(s->pb) / (TS_PACKET_SIZE + 4)) % 32;
+ int packets = (ts->total_size / (TS_PACKET_SIZE + 4)) % 32;
I'd rather keep avio_tell(s->pb) here, because I have a patch series which
changes m2ts mode to use proper CBR muxing, and that must keep track the
number of "fake" null packets written to maintain proper PCR:
https://github.com/cus/ffmpeg/commits/mpegts2
(Note that that series tracks the number of packets and not "total_size",
but they are the same, so after you apply this patch that series can be
easily adopted).
Thanks,
Marton
while (packets++ < 32)
mpegts_insert_null_packet(s);
}
--
1.8.3.1
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