On 11/19/2021 1:43 PM, Andreas Rheinhardt wrote:
send_frame_to_filters() sends a frame to all the filters that
need said frame; for every filter except the last one this involves
creating a reference to the frame, because
av_buffersrc_add_frame_flags() by default takes ownership of
the supplied references. Yet said function has a flag which
changes its behaviour to create a reference itself.
This commit uses this flag and stops creating the references itself;
this allows to remove the spare AVFrame holding the temporary
references; it also avoids unreferencing said frame.

Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@outlook.com>
---
  fftools/ffmpeg.c     | 22 +++++++---------------
  fftools/ffmpeg.h     |  1 -
  fftools/ffmpeg_opt.c |  4 ----
  3 files changed, 7 insertions(+), 20 deletions(-)

diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index e88ca554ae..bdbbc23cfd 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -633,7 +633,6 @@ static void ffmpeg_cleanup(int ret)
          InputStream *ist = input_streams[i];
av_frame_free(&ist->decoded_frame);
-        av_frame_free(&ist->filter_frame);
          av_packet_free(&ist->pkt);
          av_dict_free(&ist->decoder_opts);
          avsubtitle_free(&ist->prev_sub.subtitle);
@@ -2171,7 +2170,7 @@ static int ifilter_has_all_input_formats(FilterGraph *fg)
      return 1;
  }
-static int ifilter_send_frame(InputFilter *ifilter, AVFrame *frame)
+static int ifilter_send_frame(InputFilter *ifilter, AVFrame *frame, int 
buffersrc_flags)
  {
      FilterGraph *fg = ifilter->graph;
      AVFrameSideData *sd;
@@ -2217,7 +2216,6 @@ static int ifilter_send_frame(InputFilter *ifilter, 
AVFrame *frame)
              AVFrame *tmp = av_frame_clone(frame);
              if (!tmp)
                  return AVERROR(ENOMEM);
-            av_frame_unref(frame);
if (!av_fifo_space(ifilter->frame_queue)) {
                  ret = av_fifo_realloc2(ifilter->frame_queue, 2 * 
av_fifo_size(ifilter->frame_queue));
@@ -2243,7 +2241,8 @@ static int ifilter_send_frame(InputFilter *ifilter, 
AVFrame *frame)
          }
      }
- ret = av_buffersrc_add_frame_flags(ifilter->filter, frame, AV_BUFFERSRC_FLAG_PUSH);
+    ret = av_buffersrc_add_frame_flags(ifilter->filter, frame,
+                                       AV_BUFFERSRC_FLAG_PUSH | 
buffersrc_flags);

nit: It may look nicer if you instead make ifilter_send_frame() like

static int ifilter_send_frame(InputStream *ist, AVFrame *frame, int idx)
{
    InputFilter *ifilter = ist->filters[idx];
    int flags = AV_BUFFERSRC_FLAG_PUSH;
    [...]
    if (idx < ist->nb_filters - 1)
        flags |= AV_BUFFERSRC_FLAG_KEEP_REF;
    ret = av_buffersrc_add_frame_flags(ifilter->filter, frame, flags);
    [...]
}

Which will simplify the code in send_frame_to_filters() below with a simple

ret = ifilter_send_frame(ist, decoded_frame, i);

      if (ret < 0) {
          if (ret != AVERROR_EOF)
              av_log(NULL, AV_LOG_ERROR, "Error while filtering: %s\n", 
av_err2str(ret));
@@ -2306,18 +2305,13 @@ static int decode(AVCodecContext *avctx, AVFrame 
*frame, int *got_frame, AVPacke
  static int send_frame_to_filters(InputStream *ist, AVFrame *decoded_frame)
  {
      int i, ret;
-    AVFrame *f;
av_assert1(ist->nb_filters > 0); /* ensure ret is initialized */
      for (i = 0; i < ist->nb_filters; i++) {
-        if (i < ist->nb_filters - 1) {
-            f = ist->filter_frame;
-            ret = av_frame_ref(f, decoded_frame);
-            if (ret < 0)
-                break;
-        } else
-            f = decoded_frame;
-        ret = ifilter_send_frame(ist->filters[i], f);
+        int flags = 0;
+        if (i < ist->nb_filters - 1)
+            flags = AV_BUFFERSRC_FLAG_KEEP_REF;
+        ret = ifilter_send_frame(ist->filters[i], decoded_frame, flags);
          if (ret == AVERROR_EOF)
              ret = 0; /* ignore */
          if (ret < 0) {
@@ -2385,7 +2379,6 @@ static int decode_audio(InputStream *ist, AVPacket *pkt, 
int *got_output,
      ist->nb_samples = decoded_frame->nb_samples;
      err = send_frame_to_filters(ist, decoded_frame);
- av_frame_unref(ist->filter_frame);
      av_frame_unref(decoded_frame);
      return err < 0 ? err : ret;
  }
@@ -2511,7 +2504,6 @@ static int decode_video(InputStream *ist, AVPacket *pkt, 
int *got_output, int64_
      err = send_frame_to_filters(ist, decoded_frame);
fail:
-    av_frame_unref(ist->filter_frame);
      av_frame_unref(decoded_frame);
      return err < 0 ? err : ret;
  }
diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
index 545ff1c8e7..ce790c4d6f 100644
--- a/fftools/ffmpeg.h
+++ b/fftools/ffmpeg.h
@@ -311,7 +311,6 @@ typedef struct InputStream {
      AVCodecContext *dec_ctx;
      const AVCodec *dec;
      AVFrame *decoded_frame;
-    AVFrame *filter_frame; /* a ref of decoded_frame, to be sent to filters */
      AVPacket *pkt;
int64_t prev_pkt_pts;
diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
index 98bd3b47b6..6732a29625 100644
--- a/fftools/ffmpeg_opt.c
+++ b/fftools/ffmpeg_opt.c
@@ -893,10 +893,6 @@ static void add_input_streams(OptionsContext *o, 
AVFormatContext *ic)
          if (!ist->decoded_frame)
              exit_program(1);
- ist->filter_frame = av_frame_alloc();
-        if (!ist->filter_frame)
-            exit_program(1);
-
          ist->pkt = av_packet_alloc();
          if (!ist->pkt)
              exit_program(1);


_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".

Reply via email to