[FFmpeg-cvslog] avcodec/v4l2_context: don't reinit output queue on dynamic resolution change event

[Ming Qian]

ffmpeg | branch: release/5.0 | Ming Qian <ming.qian at nxp.com> | Tue Jan  4 17:08:30 2022 +0800| [91b459ab23bfb6e7dea42f71519df2aece5751a0] | committer: Andriy Gelman

avcodec/v4l2_context: don't reinit output queue on dynamic resolution change event

Reference:
linux/Documentation/userspace-api/media/v4l/dev-decoder.rst
    "During the resolution change sequence, the OUTPUT queue must remain
     streaming. Calling VIDIOC_STREAMOFF() on the OUTPUT queue would
     abort the sequence and initiate a seek.

     In principle, the OUTPUT queue operates separately from the CAPTURE
     queue and this remains true for the duration of the entire
     resolution change sequence as well."

Reviewed-by: Andriy Gelman <andriy.gelman at gmail.com>
Signed-off-by: Ming Qian <ming.qian at nxp.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=91b459ab23bfb6e7dea42f71519df2aece5751a0
---

 libavcodec/v4l2_context.c | 27 ++-------------------------
 1 file changed, 2 insertions(+), 25 deletions(-)

diff --git a/libavcodec/v4l2_context.c b/libavcodec/v4l2_context.c
index ff1ea8e57b..dda5157698 100644
--- a/libavcodec/v4l2_context.c
+++ b/libavcodec/v4l2_context.c
@@ -162,9 +162,8 @@ static int v4l2_handle_event(V4L2Context *ctx)
 {
     V4L2m2mContext *s = ctx_to_m2mctx(ctx);
     struct v4l2_format cap_fmt = s->capture.format;
-    struct v4l2_format out_fmt = s->output.format;
     struct v4l2_event evt = { 0 };
-    int full_reinit, reinit, ret;
+    int reinit, ret;
 
     ret = ioctl(s->fd, VIDIOC_DQEVENT, &evt);
     if (ret < 0) {
@@ -180,25 +179,12 @@ static int v4l2_handle_event(V4L2Context *ctx)
     if (evt.type != V4L2_EVENT_SOURCE_CHANGE)
         return 0;
 
-    ret = ioctl(s->fd, VIDIOC_G_FMT, &out_fmt);
-    if (ret) {
-        av_log(logger(ctx), AV_LOG_ERROR, "%s VIDIOC_G_FMT\n", s->output.name);
-        return 0;
-    }
-
     ret = ioctl(s->fd, VIDIOC_G_FMT, &cap_fmt);
     if (ret) {
         av_log(logger(ctx), AV_LOG_ERROR, "%s VIDIOC_G_FMT\n", s->capture.name);
         return 0;
     }
 
-    full_reinit = v4l2_resolution_changed(&s->output, &out_fmt);
-    if (full_reinit) {
-        s->output.height = v4l2_get_height(&out_fmt);
-        s->output.width = v4l2_get_width(&out_fmt);
-        s->output.sample_aspect_ratio = v4l2_get_sar(&s->output);
-    }
-
     reinit = v4l2_resolution_changed(&s->capture, &cap_fmt);
     if (reinit) {
         s->capture.height = v4l2_get_height(&cap_fmt);
@@ -206,18 +192,9 @@ static int v4l2_handle_event(V4L2Context *ctx)
         s->capture.sample_aspect_ratio = v4l2_get_sar(&s->capture);
     }
 
-    if (full_reinit || reinit)
+    if (reinit)
         s->reinit = 1;
 
-    if (full_reinit) {
-        ret = ff_v4l2_m2m_codec_full_reinit(s);
-        if (ret) {
-            av_log(logger(ctx), AV_LOG_ERROR, "v4l2_m2m_codec_full_reinit\n");
-            return AVERROR(EINVAL);
-        }
-        goto reinit_run;
-    }
-
     if (reinit) {
         if (s->avctx)
             ret = ff_set_dimensions(s->avctx, s->capture.width, s->capture.height);