diff mbox series

[FFmpeg-devel,v5,5/7] avcodec/v4l2_context: resume the decoding process after source change event received.

Message ID 20220104090836.31660-5-ming.qian@nxp.com
State Accepted
Commit 35a9307beb6c179a5e517c0d90d5991ed45c07ac
Headers show
Series [FFmpeg-devel,v5,1/7] avcodec/v4l2_context: don't reinit output queue when dynamic resolution change | expand

Checks

Context Check Description
andriy/make_x86 success Make finished
andriy/make_fate_x86 success Make fate finished
andriy/make_ppc success Make finished
andriy/make_fate_ppc fail Make fate failed

Commit Message

Ming Qian Jan. 4, 2022, 9:08 a.m. UTC 
client need to resume the decoding process
after it dequeues the source change event.
no matter what's the return value of v4l2_resolution_changed().
if the client doesn't resume the decoding process,
the decoder may keep waiting

in documentation of v4l2 stateful decoder, we can see the following
description:
	The client must continue the sequence as described below to
	continue the decoding process.
	1.  Dequeue the source change event.
		Important
		A source change triggers an implicit decoder drain,
		similar to the explicit Drain sequence. The decoder is
		stopped after it completes. The decoding process must be
		resumed with either a pair of calls to
		VIDIOC_STREAMOFF() and VIDIOC_STREAMON() on the CAPTURE
		queue, or a call to VIDIOC_DECODER_CMD() with the
		V4L2_DEC_CMD_START command.
	2.  Continue with the Capture Setup sequence.

Signed-off-by: Ming Qian <ming.qian@nxp.com>
---
 libavcodec/v4l2_context.c | 31 +++++++++++--------------------
 1 file changed, 11 insertions(+), 20 deletions(-)

Comments

Andriy Gelman Jan. 4, 2022, 10:41 p.m. UTC | #1 
On Tue, 04. Jan 17:08, Ming Qian wrote:
> client need to resume the decoding process
> after it dequeues the source change event.
> no matter what's the return value of v4l2_resolution_changed().
> if the client doesn't resume the decoding process,
> the decoder may keep waiting
> 
> in documentation of v4l2 stateful decoder, we can see the following
> description:
> 	The client must continue the sequence as described below to
> 	continue the decoding process.
> 	1.  Dequeue the source change event.
> 		Important
> 		A source change triggers an implicit decoder drain,
> 		similar to the explicit Drain sequence. The decoder is
> 		stopped after it completes. The decoding process must be
> 		resumed with either a pair of calls to
> 		VIDIOC_STREAMOFF() and VIDIOC_STREAMON() on the CAPTURE
> 		queue, or a call to VIDIOC_DECODER_CMD() with the
> 		V4L2_DEC_CMD_START command.
> 	2.  Continue with the Capture Setup sequence.
> 

This is just a clean up to remove the reinit variable so the commit title and
description are wrong.

Thanks,
Andriy Gelman Jan. 12, 2022, 4:44 a.m. UTC | #2 
On Tue, 04. Jan 17:41, Andriy Gelman wrote:
> On Tue, 04. Jan 17:08, Ming Qian wrote:
> > client need to resume the decoding process
> > after it dequeues the source change event.
> > no matter what's the return value of v4l2_resolution_changed().
> > if the client doesn't resume the decoding process,
> > the decoder may keep waiting
> > 
> > in documentation of v4l2 stateful decoder, we can see the following
> > description:
> > 	The client must continue the sequence as described below to
> > 	continue the decoding process.
> > 	1.  Dequeue the source change event.
> > 		Important
> > 		A source change triggers an implicit decoder drain,
> > 		similar to the explicit Drain sequence. The decoder is
> > 		stopped after it completes. The decoding process must be
> > 		resumed with either a pair of calls to
> > 		VIDIOC_STREAMOFF() and VIDIOC_STREAMON() on the CAPTURE
> > 		queue, or a call to VIDIOC_DECODER_CMD() with the
> > 		V4L2_DEC_CMD_START command.
> > 	2.  Continue with the Capture Setup sequence.
> > 
> 
> This is just a clean up to remove the reinit variable so the commit title and
> description are wrong.
> 

Updated the commit message and pushed.

Thanks,
diff mbox series

Patch

diff --git a/libavcodec/v4l2_context.c b/libavcodec/v4l2_context.c
index 0a0f5b226960..b7b584dfbef6 100644
--- a/libavcodec/v4l2_context.c
+++ b/libavcodec/v4l2_context.c
@@ -180,7 +180,7 @@  static int v4l2_handle_event(V4L2Context *ctx)
     V4L2m2mContext *s = ctx_to_m2mctx(ctx);
     struct v4l2_format cap_fmt = s->capture.format;
     struct v4l2_event evt = { 0 };
-    int reinit, ret;
+    int ret;
 
     ret = ioctl(s->fd, VIDIOC_DQEVENT, &evt);
     if (ret < 0) {
@@ -202,8 +202,7 @@  static int v4l2_handle_event(V4L2Context *ctx)
         return 0;
     }
 
-    reinit = v4l2_resolution_changed(&s->capture, &cap_fmt);
-    if (reinit) {
+    if (v4l2_resolution_changed(&s->capture, &cap_fmt)) {
         s->capture.height = v4l2_get_height(&cap_fmt);
         s->capture.width = v4l2_get_width(&cap_fmt);
         s->capture.sample_aspect_ratio = v4l2_get_sar(&s->capture);
@@ -212,28 +211,20 @@  static int v4l2_handle_event(V4L2Context *ctx)
         return 0;
     }
 
-    if (reinit)
-        s->reinit = 1;
+    s->reinit = 1;
 
-    if (reinit) {
-        if (s->avctx)
-            ret = ff_set_dimensions(s->avctx, s->capture.width, s->capture.height);
-        if (ret < 0)
-            av_log(logger(ctx), AV_LOG_WARNING, "update avcodec height and width\n");
+    if (s->avctx)
+        ret = ff_set_dimensions(s->avctx, s->capture.width, s->capture.height);
+    if (ret < 0)
+        av_log(logger(ctx), AV_LOG_WARNING, "update avcodec height and width\n");
 
-        ret = ff_v4l2_m2m_codec_reinit(s);
-        if (ret) {
-            av_log(logger(ctx), AV_LOG_ERROR, "v4l2_m2m_codec_reinit\n");
-            return AVERROR(EINVAL);
-        }
-        goto reinit_run;
+    ret = ff_v4l2_m2m_codec_reinit(s);
+    if (ret) {
+        av_log(logger(ctx), AV_LOG_ERROR, "v4l2_m2m_codec_reinit\n");
+        return AVERROR(EINVAL);
     }
 
-    /* dummy event received */
-    return 0;
-
     /* reinit executed */
-reinit_run:
     return 1;
 }