[FFmpeg-devel] [PATCH 4/6] doc/examples/transcoding: stop constantly allocating AVFrames
Anton Khirnov
anton at khirnov.net
Mon Nov 2 15:17:15 EET 2020
Allocate just one and reuse it.
---
doc/examples/transcoding.c | 60 ++++++++++++++++++++------------------
1 file changed, 31 insertions(+), 29 deletions(-)
diff --git a/doc/examples/transcoding.c b/doc/examples/transcoding.c
index e48837cbd2..4a45717bea 100644
--- a/doc/examples/transcoding.c
+++ b/doc/examples/transcoding.c
@@ -41,12 +41,16 @@ typedef struct FilteringContext {
AVFilterContext *buffersink_ctx;
AVFilterContext *buffersrc_ctx;
AVFilterGraph *filter_graph;
+
+ AVFrame *filtered_frame;
} FilteringContext;
static FilteringContext *filter_ctx;
typedef struct StreamContext {
AVCodecContext *dec_ctx;
AVCodecContext *enc_ctx;
+
+ AVFrame *dec_frame;
} StreamContext;
static StreamContext *stream_ctx;
@@ -102,6 +106,10 @@ static int open_input_file(const char *filename)
}
}
stream_ctx[i].dec_ctx = codec_ctx;
+
+ stream_ctx[i].dec_frame = av_frame_alloc();
+ if (!stream_ctx[i].dec_frame)
+ return AVERROR(ENOMEM);
}
av_dump_format(ifmt_ctx, 0, filename, 0);
@@ -398,6 +406,10 @@ static int init_filters(void)
stream_ctx[i].enc_ctx, filter_spec);
if (ret)
return ret;
+
+ filter_ctx[i].filtered_frame = av_frame_alloc();
+ if (!filter_ctx[i].filtered_frame)
+ return AVERROR(ENOMEM);
}
return 0;
}
@@ -420,7 +432,6 @@ static int encode_write_frame(AVFrame *filt_frame, unsigned int stream_index, in
av_init_packet(&enc_pkt);
ret = enc_func(stream_ctx[stream_index].enc_ctx, &enc_pkt,
filt_frame, got_frame);
- av_frame_free(&filt_frame);
if (ret < 0)
return ret;
if (!(*got_frame))
@@ -440,12 +451,12 @@ static int encode_write_frame(AVFrame *filt_frame, unsigned int stream_index, in
static int filter_encode_write_frame(AVFrame *frame, unsigned int stream_index)
{
+ FilteringContext *filter = &filter_ctx[stream_index];
int ret;
- AVFrame *filt_frame;
av_log(NULL, AV_LOG_INFO, "Pushing decoded frame to filters\n");
/* push the decoded frame into the filtergraph */
- ret = av_buffersrc_add_frame_flags(filter_ctx[stream_index].buffersrc_ctx,
+ ret = av_buffersrc_add_frame_flags(filter->buffersrc_ctx,
frame, 0);
if (ret < 0) {
av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n");
@@ -454,14 +465,9 @@ static int filter_encode_write_frame(AVFrame *frame, unsigned int stream_index)
/* pull filtered frames from the filtergraph */
while (1) {
- filt_frame = av_frame_alloc();
- if (!filt_frame) {
- ret = AVERROR(ENOMEM);
- break;
- }
av_log(NULL, AV_LOG_INFO, "Pulling filtered frame from filters\n");
- ret = av_buffersink_get_frame(filter_ctx[stream_index].buffersink_ctx,
- filt_frame);
+ ret = av_buffersink_get_frame(filter->buffersink_ctx,
+ filter->filtered_frame);
if (ret < 0) {
/* if no more frames for output - returns AVERROR(EAGAIN)
* if flushed and no more frames for output - returns AVERROR_EOF
@@ -469,12 +475,12 @@ static int filter_encode_write_frame(AVFrame *frame, unsigned int stream_index)
*/
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
ret = 0;
- av_frame_free(&filt_frame);
break;
}
- filt_frame->pict_type = AV_PICTURE_TYPE_NONE;
- ret = encode_write_frame(filt_frame, stream_index, NULL);
+ filter->filtered_frame->pict_type = AV_PICTURE_TYPE_NONE;
+ ret = encode_write_frame(filter->filtered_frame, stream_index, NULL);
+ av_frame_unref(filter->filtered_frame);
if (ret < 0)
break;
}
@@ -506,7 +512,6 @@ int main(int argc, char **argv)
{
int ret;
AVPacket packet = { .data = NULL, .size = 0 };
- AVFrame *frame = NULL;
enum AVMediaType type;
unsigned int stream_index;
unsigned int i;
@@ -535,33 +540,27 @@ int main(int argc, char **argv)
stream_index);
if (filter_ctx[stream_index].filter_graph) {
+ StreamContext *stream = &stream_ctx[stream_index];
+
av_log(NULL, AV_LOG_DEBUG, "Going to reencode&filter the frame\n");
- frame = av_frame_alloc();
- if (!frame) {
- ret = AVERROR(ENOMEM);
- break;
- }
+
av_packet_rescale_ts(&packet,
ifmt_ctx->streams[stream_index]->time_base,
- stream_ctx[stream_index].dec_ctx->time_base);
+ stream->dec_ctx->time_base);
dec_func = (type == AVMEDIA_TYPE_VIDEO) ? avcodec_decode_video2 :
avcodec_decode_audio4;
- ret = dec_func(stream_ctx[stream_index].dec_ctx, frame,
+ ret = dec_func(stream->dec_ctx, stream->dec_frame,
&got_frame, &packet);
if (ret < 0) {
- av_frame_free(&frame);
av_log(NULL, AV_LOG_ERROR, "Decoding failed\n");
break;
}
if (got_frame) {
- frame->pts = frame->best_effort_timestamp;
- ret = filter_encode_write_frame(frame, stream_index);
- av_frame_free(&frame);
+ stream->dec_frame->pts = stream->dec_frame->best_effort_timestamp;
+ ret = filter_encode_write_frame(stream->dec_frame, stream_index);
if (ret < 0)
goto end;
- } else {
- av_frame_free(&frame);
}
} else {
/* remux this frame without reencoding */
@@ -598,13 +597,16 @@ int main(int argc, char **argv)
av_write_trailer(ofmt_ctx);
end:
av_packet_unref(&packet);
- av_frame_free(&frame);
for (i = 0; i < ifmt_ctx->nb_streams; i++) {
avcodec_free_context(&stream_ctx[i].dec_ctx);
if (ofmt_ctx && ofmt_ctx->nb_streams > i && ofmt_ctx->streams[i] && stream_ctx[i].enc_ctx)
avcodec_free_context(&stream_ctx[i].enc_ctx);
- if (filter_ctx && filter_ctx[i].filter_graph)
+ if (filter_ctx && filter_ctx[i].filter_graph) {
avfilter_graph_free(&filter_ctx[i].filter_graph);
+ av_frame_free(&filter_ctx[i].filtered_frame);
+ }
+
+ av_frame_free(&stream_ctx[i].dec_frame);
}
av_free(filter_ctx);
av_free(stream_ctx);
--
2.28.0
More information about the ffmpeg-devel
mailing list