On Fri, Aug 26, 2022 at 1:42 PM Sebastian Beckmann <beckmann.sebast...@outlook.de> wrote: > > Adds an option to use constant bitrate instead of average bitrate to the > videotoolbox encoders. This is enabled via -constant_bit_rate true. > macOS 13 is required for this option to work. > > Signed-off-by: Sebastian Beckmann <beckmann.sebast...@outlook.de> > --- > libavcodec/videotoolboxenc.c | 37 +++++++++++++++++++++++++++++++++--- > 1 file changed, 34 insertions(+), 3 deletions(-) > > diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c > index 823e5ad94e..9eb6fe09a2 100644 > --- a/libavcodec/videotoolboxenc.c > +++ b/libavcodec/videotoolboxenc.c > @@ -101,6 +101,7 @@ static struct{ > CFStringRef kVTCompressionPropertyKey_RealTime; > CFStringRef kVTCompressionPropertyKey_TargetQualityForAlpha; > CFStringRef kVTCompressionPropertyKey_PrioritizeEncodingSpeedOverQuality; > + CFStringRef kVTCompressionPropertyKey_ConstantBitRate; > > CFStringRef > kVTVideoEncoderSpecification_EnableHardwareAcceleratedVideoEncoder; > CFStringRef > kVTVideoEncoderSpecification_RequireHardwareAcceleratedVideoEncoder; > @@ -164,6 +165,7 @@ static void loadVTEncSymbols(){ > "TargetQualityForAlpha"); > GET_SYM(kVTCompressionPropertyKey_PrioritizeEncodingSpeedOverQuality, > "PrioritizeEncodingSpeedOverQuality"); > + GET_SYM(kVTCompressionPropertyKey_ConstantBitRate, "ConstantBitRate"); > > > GET_SYM(kVTVideoEncoderSpecification_EnableHardwareAcceleratedVideoEncoder, > "EnableHardwareAcceleratedVideoEncoder"); > @@ -236,6 +238,7 @@ typedef struct VTEncContext { > int realtime; > int frames_before; > int frames_after; > + bool constant_bit_rate; > > int allow_sw; > int require_sw; > @@ -1073,12 +1076,22 @@ static bool vtenc_qscale_enabled(void) > return !TARGET_OS_IPHONE && TARGET_CPU_ARM64; > } > > +// constant bit rate only on Macs with Apple Silicon running macOS 13 > (Ventura) or newer > +static bool vtenc_constant_bit_rate_enabled(void) > +{ > + if (__builtin_available(macOS 13, *)) > + return !TARGET_OS_IPHONE && TARGET_CPU_ARM64; > + else > + return false; > +}
vtenc_constant_bit_rate_available() may be a better name for this function, its the user that enables it through the flag you added > static int vtenc_create_encoder(AVCodecContext *avctx, > CMVideoCodecType codec_type, > CFStringRef profile_level, > CFNumberRef gamma_level, > CFDictionaryRef enc_info, > CFDictionaryRef pixel_buffer_info, > + bool constant_bit_rate, > VTCompressionSessionRef *session) > { > VTEncContext *vtctx = avctx->priv_data; > @@ -1122,6 +1135,11 @@ static int vtenc_create_encoder(AVCodecContext > *avctx, > return AVERROR_EXTERNAL; > } > > + if (constant_bit_rate && !vtenc_constant_bit_rate_enabled()) { > + av_log(avctx, AV_LOG_ERROR, "Error: -constant_bit_rate true not > available for encoder.\n"); > + return AVERROR_EXTERNAL; > + } > + > if (avctx->flags & AV_CODEC_FLAG_QSCALE) { > quality = quality >= 100 ? 1.0 : quality / 100; > quality_num = CFNumberCreate(kCFAllocatorDefault, > @@ -1139,9 +1157,16 @@ static int vtenc_create_encoder(AVCodecContext > *avctx, > &bit_rate); > if (!bit_rate_num) return AVERROR(ENOMEM); > > - status = VTSessionSetProperty(vtctx->session, > - > kVTCompressionPropertyKey_AverageBitRate, > - bit_rate_num); > + if (constant_bit_rate) { > + status = VTSessionSetProperty(vtctx->session, > + > compat_keys.kVTCompressionPropertyKey_ConstantBitRate, > + bit_rate_num); > + } else { > + status = VTSessionSetProperty(vtctx->session, > + > kVTCompressionPropertyKey_AverageBitRate, > + bit_rate_num); > + } > + > CFRelease(bit_rate_num); > } > > @@ -1530,6 +1555,7 @@ static int vtenc_configure_encoder(AVCodecContext > *avctx) > gamma_level, > enc_info, > pixel_buffer_info, > + vtctx->constant_bit_rate, > &vtctx->session); > > init_cleanup: > @@ -2532,6 +2558,7 @@ static int vtenc_populate_extradata(AVCodecContext > *avctx, > gamma_level, > enc_info, > pixel_buffer_info, > + vtctx->constant_bit_rate, > &vtctx->session); > if (status) > goto pe_cleanup; > @@ -2727,6 +2754,8 @@ static const AVOption h264_options[] = { > > { "a53cc", "Use A53 Closed Captions (if available)", OFFSET(a53_cc), > AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, VE }, > > + { "constant_bit_rate", "Require constant bit rate (macOS 13 or newer)", > OFFSET(constant_bit_rate), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE }, > + > COMMON_OPTIONS > { NULL }, > }; > @@ -2760,6 +2789,8 @@ static const AVOption hevc_options[] = { > > { "alpha_quality", "Compression quality for the alpha channel", > OFFSET(alpha_quality), AV_OPT_TYPE_DOUBLE, { .dbl = 0.0 }, 0.0, 1.0, VE }, > > + { "constant_bit_rate", "Require constant bit rate (macOS 13 or newer)", > OFFSET(constant_bit_rate), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, VE }, > + > COMMON_OPTIONS > { NULL }, > }; > -- > 2.37.0 (Apple Git-136) > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".