[FFmpeg-devel] [PATCH] libavcodec/videotoolboxenc.c: add option to hevc encoder to prioritize speed.

[Rick Kern]

On Sat, Apr 23, 2022 at 8:31 AM Simone Karin Lehmann <simone at lisanet.de>
wrote:

>
>
> > Am 22.04.2022 um 18:52 schrieb Thilo Borgmann <thilo.borgmann at mail.de>:
> >
> >
>
> > For that version I get:
> >
> > libavcodec/videotoolboxenc.c:1153:39: error: use of undeclared
> identifier 'kVTCompressionPropertyKey_PrioritizeEncodingSpeedOverQuality'
> >
> kVTCompressionPropertyKey_PrioritizeEncodingSpeedOverQuality,
> >                                      ^
> >
> > Should require some OSX version dependency via #if'ery somewhere sane.
> Like
> > #if !TARGET_OS_IPHONE && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1070
> >
> > or similar.
>
> If I understand the code correctly, it seems to me to be bettter to add
> kVTCompressionPropertyKey_PrioritizeEncodingSpeedOverQuality to the
> compat_keys struct.
>
> And digging through the SDK headers I’ve found that this property is
> available for h264 and ProRes encoders too. But since the SDK states that
> this property defaults to FALSE for h264 and hevc and to TRUE for ProRes I
> didn’t add it to the COMMON_OPTIONS but to each encoder options, because I
> didn’t want to make a regression to the ProRes or enabling it by default
> for h264 and hevc. Hope that’s ok.
>
> Here’s the resulting patch
>
> Regards
> Simone
>
>
> Signed-off-by: Simone Karin Lehmann <simone at lisanet.de <mailto:
> simone at lisanet.de>>
> ---
> libavcodec/videotoolboxenc.c | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
> index 270496b7a7..462d2a8fb6 100644
> --- a/libavcodec/videotoolboxenc.c
> +++ b/libavcodec/videotoolboxenc.c
> @@ -100,6 +100,7 @@ static struct{
>
>     CFStringRef kVTCompressionPropertyKey_RealTime;
>     CFStringRef kVTCompressionPropertyKey_TargetQualityForAlpha;
> +    CFStringRef
> kVTCompressionPropertyKey_PrioritizeEncodingSpeedOverQuality;
>
>     CFStringRef
> kVTVideoEncoderSpecification_EnableHardwareAcceleratedVideoEncoder;
>     CFStringRef
> kVTVideoEncoderSpecification_RequireHardwareAcceleratedVideoEncoder;
> @@ -161,6 +162,8 @@ static void loadVTEncSymbols(){
>     GET_SYM(kVTCompressionPropertyKey_RealTime, "RealTime");
>     GET_SYM(kVTCompressionPropertyKey_TargetQualityForAlpha,
>             "TargetQualityForAlpha");
> +    GET_SYM(kVTCompressionPropertyKey_PrioritizeEncodingSpeedOverQuality,
> +            "PrioritizeEncodingSpeedOverQuality");
>
>
> GET_SYM(kVTVideoEncoderSpecification_EnableHardwareAcceleratedVideoEncoder,
>             "EnableHardwareAcceleratedVideoEncoder");
> @@ -237,6 +240,7 @@ typedef struct VTEncContext {
>     int allow_sw;
>     int require_sw;
>     double alpha_quality;
> +    int prio_speed;
>
>     bool flushing;
>     int has_b_frames;
> @@ -1146,6 +1150,16 @@ static int vtenc_create_encoder(AVCodecContext
>  *avctx,
>         return AVERROR_EXTERNAL;
>     }
>
> +    // prioritize speed over quality
> +    if (vtctx->prio_speed) {

+        status = VTSessionSetProperty(vtctx->session,
> +
> compat_keys.kVTCompressionPropertyKey_PrioritizeEncodingSpeedOverQuality,
> +                                      kCFBooleanTrue);
> +        if (status) {
> +            av_log(avctx, AV_LOG_WARNING,
> "PrioritizeEncodingSpeedOverQuality property is not supported on this
> device. Ignoring.\n");
> +        }
> +    }
> +
>     if ((vtctx->codec_id == AV_CODEC_ID_H264 || vtctx->codec_id ==
> AV_CODEC_ID_HEVC)
>             && max_rate > 0) {
>         bytes_per_second_value = max_rate >> 3;
> @@ -2711,6 +2725,7 @@ static const AVOption h264_options[] = {
>     { "ac",    "CABAC entropy coding", 0, AV_OPT_TYPE_CONST, { .i64 =
> VT_CABAC }, INT_MIN, INT_MAX, VE, "coder" },
>
>     { "a53cc", "Use A53 Closed Captions (if available)", OFFSET(a53_cc),
> AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, VE },
> +    { "prio_speed", "prioritize encoding speed", OFFSET(prio_speed),
> AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE },
>
It might be simpler to make the default value of prio_speed -1, and set
this property on the encoder session only when it's non-negative. Then we
won't need to worry about the default value changing for different codecs
or different OS versions. It could also be moved into COMMON_OPTIONS in
this case.


>
>     COMMON_OPTIONS
>     { NULL },
> @@ -2745,6 +2760,7 @@ static const AVOption hevc_options[] = {
>     { "main10",   "Main10 Profile",   0, AV_OPT_TYPE_CONST, { .i64 =
> HEVC_PROF_MAIN10 }, INT_MIN, INT_MAX, VE, "profile" },
>
>     { "alpha_quality", "Compression quality for the alpha channel",
> OFFSET(alpha_quality), AV_OPT_TYPE_DOUBLE, { .dbl = 0.0 }, 0.0, 1.0, VE },
> +    { "prio_speed", "prioritize encoding speed", OFFSET(prio_speed),
> AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE },
>
>     COMMON_OPTIONS
>     { NULL },
> @@ -2785,6 +2801,8 @@ static const AVOption prores_options[] = {
>     { "4444",     "ProRes 4444",                                   0,
> AV_OPT_TYPE_CONST, { .i64 = FF_PROFILE_PRORES_4444 },        INT_MIN,
> INT_MAX, VE, "profile" },
>     { "xq",       "ProRes 4444 XQ",                                0,
> AV_OPT_TYPE_CONST, { .i64 = FF_PROFILE_PRORES_XQ },          INT_MIN,
> INT_MAX, VE, "profile" },
>
> +  { "prio_speed", "prioritize encoding speed", OFFSET(prio_speed),
> AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, VE },
> +
>     COMMON_OPTIONS
>     { NULL },
> };
> --
> 2.32.0 (Apple Git-132)
>
>
>
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