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

[Simone Karin Lehmann]

> Am 14.04.2022 um 10:13 schrieb Thilo Borgmann <thilo.borgmann at mail.de>:
> 
> Hi,
> 
>>> diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
>>> index 418ff00b8d..ab0dad6cbc 100644
>>> --- a/libavcodec/videotoolboxenc.c
>>> +++ b/libavcodec/videotoolboxenc.c
>>> @@ -236,6 +236,7 @@ typedef struct VTEncContext {
>>>     int allow_sw;
>>>     int require_sw;
>>>     double alpha_quality;
>>> +    int64_t prio_speed;
> 
> int64_t is definitely overkill.

I just wanted to make it consistent with hevc_options[] and other variables of AV_OPT_TYPE_BOOL. these are noted as .i64. 
Anyway, I changed it to int.

> 
>>> 
>>>     bool flushing;
>>>     int has_b_frames;
>>> @@ -1145,6 +1146,17 @@ static int vtenc_create_encoder(AVCodecContext   *avctx,
>>>         return AVERROR_EXTERNAL;
>>>     }
>>> 
>>> +    // prioritize speed over quality
>>> +    if (vtctx->prio_speed) {
>>> +        status = VTSessionSetProperty(vtctx->session,
>>> +                                      kVTCompressionPropertyKey_PrioritizeEncodingSpeedOverQuality,
>>> +                                      kCFBooleanTrue);
>>> +        if (status) {
>>> +            av_log(avctx, AV_LOG_ERROR, "Error setting PrioritizeEncodingSpeedOverQuality property: %d\n", status);
>>> +            return AVERROR_EXTERNAL;
>>> +        }
> 
> If its called to priotize speed over qual, why not just print a warning and continue without this option?

You’re right. A warning seems much better. Changed this too.

Here’s the modified patch. 

Signed-off-by: Simone Karin Lehmann <simone at lisanet.de>
---
 libavcodec/videotoolboxenc.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
index 270496b7a7..cf931569d1 100644
--- a/libavcodec/videotoolboxenc.c
+++ b/libavcodec/videotoolboxenc.c
@@ -237,6 +237,7 @@ typedef struct VTEncContext {
     int allow_sw;
     int require_sw;
     double alpha_quality;
+    int prio_speed;
 
     bool flushing;
     int has_b_frames;
@@ -1146,6 +1147,16 @@ static int vtenc_create_encoder(AVCodecContext   *avctx,
         return AVERROR_EXTERNAL;
     }
 
+    // prioritize speed over quality
+    if (vtctx->prio_speed) {
+        status = VTSessionSetProperty(vtctx->session,
+                                      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;
@@ -2745,6 +2756,7 @@ 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 },
-- 
2.32.0 (Apple Git-132)