diff mbox series

[FFmpeg-devel,2/2] lavc/videotoolboxenc: enable low-latency mode for HEVC

Message ID 20230831144932.575654-2-mypopydev@gmail.com
State New
Headers show
Series [FFmpeg-devel,1/2] avdevice/decklink_dec: add explicit specifier | expand

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Context Check Description
andriy/make_x86 success Make finished
andriy/make_fate_x86 success Make fate finished

Commit Message

Jun Zhao Aug. 31, 2023, 2:49 p.m. UTC
Enable the HEVC encoder that supports low-latency mode.

Signed-off-by: Jun Zhao <barryjzhao@tencent.com>
---
 libavcodec/videotoolboxenc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Zhao Zhili Aug. 31, 2023, 6:12 p.m. UTC | #1
> From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of Jun Zhao
> Sent: 2023年8月31日 22:50
> To: ffmpeg-devel@ffmpeg.org
> Cc: Jun Zhao <barryjzhao@tencent.com>; Jun Zhao <mypopydev@gmail.com>
> Subject: [FFmpeg-devel] [PATCH 2/2] lavc/videotoolboxenc: enable low-latency mode for HEVC
> 
> Enable the HEVC encoder that supports low-latency mode.
> 
> Signed-off-by: Jun Zhao <barryjzhao@tencent.com>
> ---
>  libavcodec/videotoolboxenc.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
> index 8e493c4f7a..bfc03787a0 100644
> --- a/libavcodec/videotoolboxenc.c
> +++ b/libavcodec/videotoolboxenc.c
> @@ -1568,7 +1568,8 @@ static int vtenc_configure_encoder(AVCodecContext *avctx)
>  #endif
> 
>      // low-latency mode: eliminate frame reordering, follow a one-in-one-out encoding mode
> -    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) && avctx->codec_id == AV_CODEC_ID_H264) {
> +    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) &&
> +        (avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == AV_CODEC_ID_HEVC)) {

How about just remove the codec_id check?
Is there any unwelcome side effects for encoders other than H264/HEVC?

>          CFDictionarySetValue(enc_info,
>                               compat_keys.kVTVideoEncoderSpecification_EnableLowLatencyRateControl,
>                               kCFBooleanTrue);
> --
> 2.25.1
> 
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
mypopy@gmail.com Sept. 1, 2023, 1:13 a.m. UTC | #2
On Fri, Sep 1, 2023 at 2:13 AM Zhao Zhili <quinkblack@foxmail.com> wrote:
>
>
> > From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of Jun Zhao
> > Sent: 2023年8月31日 22:50
> > To: ffmpeg-devel@ffmpeg.org
> > Cc: Jun Zhao <barryjzhao@tencent.com>; Jun Zhao <mypopydev@gmail.com>
> > Subject: [FFmpeg-devel] [PATCH 2/2] lavc/videotoolboxenc: enable low-latency mode for HEVC
> >
> > Enable the HEVC encoder that supports low-latency mode.
> >
> > Signed-off-by: Jun Zhao <barryjzhao@tencent.com>
> > ---
> >  libavcodec/videotoolboxenc.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
> > index 8e493c4f7a..bfc03787a0 100644
> > --- a/libavcodec/videotoolboxenc.c
> > +++ b/libavcodec/videotoolboxenc.c
> > @@ -1568,7 +1568,8 @@ static int vtenc_configure_encoder(AVCodecContext *avctx)
> >  #endif
> >
> >      // low-latency mode: eliminate frame reordering, follow a one-in-one-out encoding mode
> > -    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) && avctx->codec_id == AV_CODEC_ID_H264) {
> > +    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) &&
> > +        (avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == AV_CODEC_ID_HEVC)) {
>
> How about just remove the codec_id check?
> Is there any unwelcome side effects for encoders other than H264/HEVC?

1. One reason is that there are now other encoders available, such as
prores_videotoolbox.

2. It may be more appropriate to use a strictly qualified check
instead of an open condition.
Zhao Zhili Sept. 1, 2023, 3:49 a.m. UTC | #3
> On Sep 1, 2023, at 09:13, mypopy@gmail.com wrote:
> 
> On Fri, Sep 1, 2023 at 2:13 AM Zhao Zhili <quinkblack@foxmail.com> wrote:
>> 
>> 
>>> From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of Jun Zhao
>>> Sent: 2023年8月31日 22:50
>>> To: ffmpeg-devel@ffmpeg.org
>>> Cc: Jun Zhao <barryjzhao@tencent.com>; Jun Zhao <mypopydev@gmail.com>
>>> Subject: [FFmpeg-devel] [PATCH 2/2] lavc/videotoolboxenc: enable low-latency mode for HEVC
>>> 
>>> Enable the HEVC encoder that supports low-latency mode.
>>> 
>>> Signed-off-by: Jun Zhao <barryjzhao@tencent.com>
>>> ---
>>> libavcodec/videotoolboxenc.c | 3 ++-
>>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>> 
>>> diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
>>> index 8e493c4f7a..bfc03787a0 100644
>>> --- a/libavcodec/videotoolboxenc.c
>>> +++ b/libavcodec/videotoolboxenc.c
>>> @@ -1568,7 +1568,8 @@ static int vtenc_configure_encoder(AVCodecContext *avctx)
>>> #endif
>>> 
>>>     // low-latency mode: eliminate frame reordering, follow a one-in-one-out encoding mode
>>> -    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) && avctx->codec_id == AV_CODEC_ID_H264) {
>>> +    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) &&
>>> +        (avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == AV_CODEC_ID_HEVC)) {
>> 
>> How about just remove the codec_id check?
>> Is there any unwelcome side effects for encoders other than H264/HEVC?
> 
> 1. One reason is that there are now other encoders available, such as
> prores_videotoolbox.
> 
> 2. It may be more appropriate to use a strictly qualified check
> instead of an open condition.

Both HEVC and ProRes failed with low_latency on my machine (with or without -allow_sw 1)

[hevc_videotoolbox @ 0x61900002a380] Error: cannot create compression session: -12902
[prores_videotoolbox @ 0x61900002a380] Error: cannot create compression session: -12902

	kVTParameterErr							= -12902,

1. FFmpeg users should have an idea whether or not to set AV_CODEC_FLAG_LOW_DELAY.
AV_CODEC_FLAG_LOW_DELAY doesn’t make sense for ProRes, but if user wants to try, let he/she
do.

2. I can’t find API to query the capability. Only VideoToolBox framework itself know how
to handle the argument. There isn’t much protect to provide for users.

Even with H.264, the results is unexpected: the input framerate is 25 but the output
framerate is 5, it dropped 80 percent frames silently.

> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
mypopy@gmail.com Sept. 1, 2023, 4:07 a.m. UTC | #4
On Fri, Sep 1, 2023 at 11:50 AM "zhilizhao(赵志立)" <quinkblack@foxmail.com> wrote:
>
>
>
> > On Sep 1, 2023, at 09:13, mypopy@gmail.com wrote:
> >
> > On Fri, Sep 1, 2023 at 2:13 AM Zhao Zhili <quinkblack@foxmail.com> wrote:
> >>
> >>
> >>> From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of Jun Zhao
> >>> Sent: 2023年8月31日 22:50
> >>> To: ffmpeg-devel@ffmpeg.org
> >>> Cc: Jun Zhao <barryjzhao@tencent.com>; Jun Zhao <mypopydev@gmail.com>
> >>> Subject: [FFmpeg-devel] [PATCH 2/2] lavc/videotoolboxenc: enable low-latency mode for HEVC
> >>>
> >>> Enable the HEVC encoder that supports low-latency mode.
> >>>
> >>> Signed-off-by: Jun Zhao <barryjzhao@tencent.com>
> >>> ---
> >>> libavcodec/videotoolboxenc.c | 3 ++-
> >>> 1 file changed, 2 insertions(+), 1 deletion(-)
> >>>
> >>> diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
> >>> index 8e493c4f7a..bfc03787a0 100644
> >>> --- a/libavcodec/videotoolboxenc.c
> >>> +++ b/libavcodec/videotoolboxenc.c
> >>> @@ -1568,7 +1568,8 @@ static int vtenc_configure_encoder(AVCodecContext *avctx)
> >>> #endif
> >>>
> >>>     // low-latency mode: eliminate frame reordering, follow a one-in-one-out encoding mode
> >>> -    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) && avctx->codec_id == AV_CODEC_ID_H264) {
> >>> +    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) &&
> >>> +        (avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == AV_CODEC_ID_HEVC)) {
> >>
> >> How about just remove the codec_id check?
> >> Is there any unwelcome side effects for encoders other than H264/HEVC?
> >
> > 1. One reason is that there are now other encoders available, such as
> > prores_videotoolbox.
> >
> > 2. It may be more appropriate to use a strictly qualified check
> > instead of an open condition.
>
> Both HEVC and ProRes failed with low_latency on my machine (with or without -allow_sw 1)
>
> [hevc_videotoolbox @ 0x61900002a380] Error: cannot create compression session: -12902
> [prores_videotoolbox @ 0x61900002a380] Error: cannot create compression session: -12902
>
>         kVTParameterErr                                                 = -12902,
>
I think you missed the other options, low delay in VT encoder need to
co-work with some other options

> 1. FFmpeg users should have an idea whether or not to set AV_CODEC_FLAG_LOW_DELAY.
> AV_CODEC_FLAG_LOW_DELAY doesn’t make sense for ProRes, but if user wants to try, let he/she
> do.
>
> 2. I can’t find API to query the capability. Only VideoToolBox framework itself know how
> to handle the argument. There isn’t much protect to provide for users.
>
Yes, now FFmpeg VT encoder didn't used the capability query, I think
need to used the some API VTCopySupportedPropertyDictionaryForEncoder
for capability query, this my next step
> Even with H.264, the results is unexpected: the input framerate is 25 but the output
> framerate is 5, it dropped 80 percent frames silently.
>
Rick Kern Sept. 1, 2023, 4:17 a.m. UTC | #5
> On Sep 1, 2023, at 12:07 AM, mypopy@gmail.com wrote:
> 
> On Fri, Sep 1, 2023 at 11:50 AM "zhilizhao(赵志立)" <quinkblack@foxmail.com> wrote:
>> 
>> 
>> 
>>>> On Sep 1, 2023, at 09:13, mypopy@gmail.com wrote:
>>> 
>>> On Fri, Sep 1, 2023 at 2:13 AM Zhao Zhili <quinkblack@foxmail.com> wrote:
>>>> 
>>>> 
>>>>> From: ffmpeg-devel <ffmpeg-devel-bounces@ffmpeg.org> On Behalf Of Jun Zhao
>>>>> Sent: 2023年8月31日 22:50
>>>>> To: ffmpeg-devel@ffmpeg.org
>>>>> Cc: Jun Zhao <barryjzhao@tencent.com>; Jun Zhao <mypopydev@gmail.com>
>>>>> Subject: [FFmpeg-devel] [PATCH 2/2] lavc/videotoolboxenc: enable low-latency mode for HEVC
>>>>> 
>>>>> Enable the HEVC encoder that supports low-latency mode.
>>>>> 
>>>>> Signed-off-by: Jun Zhao <barryjzhao@tencent.com>
>>>>> ---
>>>>> libavcodec/videotoolboxenc.c | 3 ++-
>>>>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>>>> 
>>>>> diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
>>>>> index 8e493c4f7a..bfc03787a0 100644
>>>>> --- a/libavcodec/videotoolboxenc.c
>>>>> +++ b/libavcodec/videotoolboxenc.c
>>>>> @@ -1568,7 +1568,8 @@ static int vtenc_configure_encoder(AVCodecContext *avctx)
>>>>> #endif
>>>>> 
>>>>>    // low-latency mode: eliminate frame reordering, follow a one-in-one-out encoding mode
>>>>> -    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) && avctx->codec_id == AV_CODEC_ID_H264) {
>>>>> +    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) &&
>>>>> +        (avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == AV_CODEC_ID_HEVC)) {
>>>> 
>>>> How about just remove the codec_id check?
>>>> Is there any unwelcome side effects for encoders other than H264/HEVC?
>>> 
>>> 1. One reason is that there are now other encoders available, such as
>>> prores_videotoolbox.
>>> 
>>> 2. It may be more appropriate to use a strictly qualified check
>>> instead of an open condition.
>> 
>> Both HEVC and ProRes failed with low_latency on my machine (with or without -allow_sw 1)
>> 
>> [hevc_videotoolbox @ 0x61900002a380] Error: cannot create compression session: -12902
>> [prores_videotoolbox @ 0x61900002a380] Error: cannot create compression session: -12902
>> 
>>        kVTParameterErr                                                 = -12902,
>> 
> I think you missed the other options, low delay in VT encoder need to
> co-work with some other options
> 
>> 1. FFmpeg users should have an idea whether or not to set AV_CODEC_FLAG_LOW_DELAY.
>> AV_CODEC_FLAG_LOW_DELAY doesn’t make sense for ProRes, but if user wants to try, let he/she
>> do.
>> 
>> 2. I can’t find API to query the capability. Only VideoToolBox framework itself know how
>> to handle the argument. There isn’t much protect to provide for users.
>> 
> Yes, now FFmpeg VT encoder didn't used the capability query, I think
> need to used the some API VTCopySupportedPropertyDictionaryForEncoder
> for capability query, this my next step
That’s a good idea. We don’t have to worry about codec checks or unexpected failures if the HEVC encoder on some devices doesn’t support it. Ideally we can print out a warn message and ignore the low-delay flag. 

>> Even with H.264, the results is unexpected: the input framerate is 25 but the output
>> framerate is 5, it dropped 80 percent frames silently.
>> 
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> 
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
diff mbox series

Patch

diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
index 8e493c4f7a..bfc03787a0 100644
--- a/libavcodec/videotoolboxenc.c
+++ b/libavcodec/videotoolboxenc.c
@@ -1568,7 +1568,8 @@  static int vtenc_configure_encoder(AVCodecContext *avctx)
 #endif
 
     // low-latency mode: eliminate frame reordering, follow a one-in-one-out encoding mode
-    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) && avctx->codec_id == AV_CODEC_ID_H264) {
+    if ((avctx->flags & AV_CODEC_FLAG_LOW_DELAY) &&
+        (avctx->codec_id == AV_CODEC_ID_H264 || avctx->codec_id == AV_CODEC_ID_HEVC)) {
         CFDictionarySetValue(enc_info,
                              compat_keys.kVTVideoEncoderSpecification_EnableLowLatencyRateControl,
                              kCFBooleanTrue);