Re: [libav-devel] [PATCH] libopenh264dec: Use a newer decoding entry point function

2019-01-26 Thread Martin Storsjö

On Sat, 26 Jan 2019, Janne Grunau wrote:


On 2019-01-25 10:39:13 +0200, Martin Storsjö wrote:

The "new" entry point actually has existed since OpenH264 1.4 in
2015, but with B-frames, this entry point is essential for actually
getting the right frames returned and reordered.

The name of this function, DecodeFrameNoDelay, is rather backwards
considering that it doesn't return the latest decoded frame immediately,
but actually does proper delaying and reordering of frames, but
it's the recommended decoding entry point.


The commit message is hard to parse. Something along below is imho
easier to understand:

| The "new" entry point actually has existed since OpenH264 1.4 in
| 2015 and is the the recommended decoding entry point.
|
| The name of this function, DecodeFrameNoDelay, is rather backwards
| considering that it doesn't return the latest decoded frame immediately,
| but actually does proper delaying and reordering of frames.


Thanks! That's indeed much more understandable.

// Martin
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Re: [libav-devel] [PATCH] libopenh264dec: Use a newer decoding entry point function

2019-01-26 Thread Janne Grunau
On 2019-01-25 10:39:13 +0200, Martin Storsjö wrote:
> The "new" entry point actually has existed since OpenH264 1.4 in
> 2015, but with B-frames, this entry point is essential for actually
> getting the right frames returned and reordered.
> 
> The name of this function, DecodeFrameNoDelay, is rather backwards
> considering that it doesn't return the latest decoded frame immediately,
> but actually does proper delaying and reordering of frames, but
> it's the recommended decoding entry point.

The commit message is hard to parse. Something along below is imho
easier to understand:

| The "new" entry point actually has existed since OpenH264 1.4 in
| 2015 and is the the recommended decoding entry point.
|
| The name of this function, DecodeFrameNoDelay, is rather backwards
| considering that it doesn't return the latest decoded frame immediately,
| but actually does proper delaying and reordering of frames.

path itsel ok,

Janne
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[libav-devel] [PATCH] libopenh264dec: Use a newer decoding entry point function

2019-01-25 Thread Martin Storsjö
The "new" entry point actually has existed since OpenH264 1.4 in
2015, but with B-frames, this entry point is essential for actually
getting the right frames returned and reordered.

The name of this function, DecodeFrameNoDelay, is rather backwards
considering that it doesn't return the latest decoded frame immediately,
but actually does proper delaying and reordering of frames, but
it's the recommended decoding entry point.
---
 libavcodec/libopenh264dec.c | 10 +-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/libavcodec/libopenh264dec.c b/libavcodec/libopenh264dec.c
index 60e4b028ec..6adf984112 100644
--- a/libavcodec/libopenh264dec.c
+++ b/libavcodec/libopenh264dec.c
@@ -109,10 +109,18 @@ static int svc_decode_frame(AVCodecContext *avctx, void 
*data,
 #endif
 } else {
 info.uiInBsTimeStamp = avpkt->pts;
+#if OPENH264_VER_AT_LEAST(1, 4)
+// Contrary to the name, DecodeFrameNoDelay actually does buffering
+// and reordering of frames, and is the recommended decoding entry
+// point since 1.4. This is essential for successfully decoding
+// B-frames.
+state = (*s->decoder)->DecodeFrameNoDelay(s->decoder, avpkt->data, 
avpkt->size, ptrs, );
+#else
 state = (*s->decoder)->DecodeFrame2(s->decoder, avpkt->data, 
avpkt->size, ptrs, );
+#endif
 }
 if (state != dsErrorFree) {
-av_log(avctx, AV_LOG_ERROR, "DecodeFrame2 failed\n");
+av_log(avctx, AV_LOG_ERROR, "DecodeFrame failed\n");
 return AVERROR_UNKNOWN;
 }
 if (info.iBufferStatus != 1) {
-- 
2.17.2 (Apple Git-113)

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