On Sat, 4 Apr 2020, James Almer wrote:
On 4/4/2020 11:47 AM, Marton Balint wrote:
This brings a performance improvement when demuxing files, most of the
improvement comes from buffer pooling unbound packets.
Yes, as i mentioned in my last reply this was my experience as well.
time ffprobe -i samples/ffmpeg-bugs/trac/ticket6132/Samsung_HDR_-_Chasing_the_Light.ts
-show_packets >/dev/null 2>&1
Before:
real 0m1.967s
user 0m1.471s
sys 0m0.493s
After:
real 0m1.497s
user 0m1.364s
sys 0m0.129s
Based on a patch of James Almer.
Signed-off-by: Marton Balint <c...@passwd.hu>
---
libavformat/mpegts.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index 7f56bacb2c..fbafc1d257 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -170,6 +170,7 @@ struct MpegTSContext {
int current_pid;
AVStream *epg_stream;
+ AVBufferPool* pools[32];
Isn't 32 way more than required?
The number of required pools is
log2(MAX_PES_PAYLOAD+AV_INPUT_BUFFER_PADDING_SIZE)+1, so currently 18, but
since as far as I know there is no compile time log2 I did not want to
limit it here so MAX_PES_PAYLOAD can still be changeable without adjusting
this.
};
#define MPEGTS_OPTIONS \
@@ -1103,6 +1104,18 @@ static int read_sl_header(PESContext *pes, SLConfigDescr
*sl,
return (get_bits_count(&gb) + 7) >> 3;
}
+static AVBufferRef *buffer_pool_get(MpegTSContext *ts, int size)
+{
+ int index = av_log2(size + AV_INPUT_BUFFER_PADDING_SIZE);
+ if (!ts->pools[index]) {
+ int pool_size = FFMIN(MAX_PES_PAYLOAD + AV_INPUT_BUFFER_PADDING_SIZE, 2
<< index);
+ ts->pools[index] = av_buffer_pool_init(pool_size, NULL);
+ if (!ts->pools[index])
+ return NULL;
+ }
+ return av_buffer_pool_get(ts->pools[index]);
+}
+
/* return non zero if a packet could be constructed */
static int mpegts_push_data(MpegTSFilter *filter,
const uint8_t *buf, int buf_size, int is_start,
@@ -1177,8 +1190,8 @@ static int mpegts_push_data(MpegTSFilter *filter,
pes->total_size = MAX_PES_PAYLOAD;
/* allocate pes buffer */
- pes->buffer = av_buffer_alloc(pes->total_size +
-
AV_INPUT_BUFFER_PADDING_SIZE);
+ pes->buffer = buffer_pool_get(ts, pes->total_size);
+
if (!pes->buffer)
return AVERROR(ENOMEM);
@@ -1351,8 +1364,7 @@ skip:
if (ret < 0)
return ret;
pes->total_size = MAX_PES_PAYLOAD;
- pes->buffer = av_buffer_alloc(pes->total_size +
-
AV_INPUT_BUFFER_PADDING_SIZE);
+ pes->buffer = buffer_pool_get(ts, pes->total_size);
if (!pes->buffer)
return AVERROR(ENOMEM);
ts->stop_parse = 1;
@@ -3200,6 +3212,9 @@ static void mpegts_free(MpegTSContext *ts)
clear_programs(ts);
+ for (i = 0; i < FF_ARRAY_ELEMS(ts->pools); i++)
+ av_buffer_pool_uninit(&ts->pools[i]);
+
for (i = 0; i < NB_PID_MAX; i++)
if (ts->pids[i])
mpegts_close_filter(ts, ts->pids[i]);
LGTM. I assume the pools for the smaller sizes will not end up being
slower than just allocating new buffers each time.
I tried to measure this but there was no significant difference.
Will apply.
Thanks,
Marton
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