[FFmpeg-devel] [PATCH] avcodec/mediacodecenc: set quality in cq mode

[Matthieu Bouron]

On Sun, Dec 17, 2023 at 1:51 PM Zhao Zhili <quinkblack at foxmail.com> wrote:
>
> From: Zhao Zhili <zhilizhao at tencent.com>
>
> From AOSP doc, these values are device and codec specific, but lower
> values generally result in more efficient (smaller-sized) encoding.
>
> For example, global_quality 50 on Pixel 6 results a 1080P 30 FPS
> HEVC with 3744 kb/s, while global_quality 80 results 28178 kb/s.
>
> Fix #10689
>
> Signed-off-by: Zhao Zhili <zhilizhao at tencent.com>
> ---
>  libavcodec/mediacodecenc.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/libavcodec/mediacodecenc.c b/libavcodec/mediacodecenc.c
> index a1ae5d5ec5..7eae542248 100644
> --- a/libavcodec/mediacodecenc.c
> +++ b/libavcodec/mediacodecenc.c
> @@ -268,8 +268,11 @@ static av_cold int mediacodec_init(AVCodecContext *avctx)
>
>      if (avctx->bit_rate)
>          ff_AMediaFormat_setInt32(format, "bitrate", avctx->bit_rate);
> -    if (s->bitrate_mode >= 0)
> +    if (s->bitrate_mode >= 0) {
>          ff_AMediaFormat_setInt32(format, "bitrate-mode", s->bitrate_mode);
> +        if (s->bitrate_mode == BITRATE_MODE_CQ && avctx->global_quality > 0)
> +            ff_AMediaFormat_setInt32(format, "quality", avctx->global_quality);
> +    }
>      // frame-rate and i-frame-interval are required to configure codec
>      if (avctx->framerate.num >= avctx->framerate.den && avctx->framerate.den > 0) {
>          s->fps = avctx->framerate.num / avctx->framerate.den;
> --
> 2.34.1
>

Does the `global_quality` value need to be checked/clamped against
`MediaCodecInfo.EncoderCapabilities.getQualityRange()` before use ?
Otherwise, LGTM.