[FFmpeg-devel] [PATCH v2] avcodec/hw_base_encode: restrict size of next_prev

[Lynne]

On 22/12/2024 05:25, Benjamin Cheng via ffmpeg-devel wrote:
> Some drivers are more strict about the size of the reference lists given
> (i.e. VAOn12 [1]). The next_prev list is used to handle multiple "L0"
> references in AV1 encode. Restrict the size of next_prev based on the
> value of ref_l0 when the GOP structure is initialized.
> 
> [1] https://github.com/intel/cartwheel-ffmpeg/issues/278
> 
> v2: fix indentation issues
> ---
>   libavcodec/hw_base_encode.c | 7 +++++--
>   libavcodec/hw_base_encode.h | 4 ++++
>   2 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/hw_base_encode.c b/libavcodec/hw_base_encode.c
> index 4d8bf4fe71..b790091d7d 100644
> --- a/libavcodec/hw_base_encode.c
> +++ b/libavcodec/hw_base_encode.c
> @@ -190,12 +190,12 @@ static void hw_base_encode_add_next_prev(FFHWBaseEncodeContext *ctx,
>           return;
>       }
>   
> -    if (ctx->nb_next_prev < MAX_PICTURE_REFERENCES) {
> +    if (ctx->nb_next_prev < ctx->ref_l0) {
>           ctx->next_prev[ctx->nb_next_prev++] = pic;
>           ++pic->ref_count[0];
>       } else {
>           --ctx->next_prev[0]->ref_count[0];
> -        for (i = 0; i < MAX_PICTURE_REFERENCES - 1; i++)
> +        for (i = 0; i < ctx->ref_l0 - 1; i++)
>               ctx->next_prev[i] = ctx->next_prev[i + 1];
>           ctx->next_prev[i] = pic;
>           ++pic->ref_count[0];
> @@ -662,6 +662,9 @@ int ff_hw_base_init_gop_structure(FFHWBaseEncodeContext *ctx, AVCodecContext *av
>                                     uint32_t ref_l0, uint32_t ref_l1,
>                                     int flags, int prediction_pre_only)
>   {
> +    ctx->ref_l0 = FFMIN(ref_l0, MAX_PICTURE_REFERENCES);
> +    ctx->ref_l1 = FFMIN(ref_l1, MAX_PICTURE_REFERENCES);
> +
>       if (flags & FF_HW_FLAG_INTRA_ONLY || avctx->gop_size <= 1) {
>           av_log(avctx, AV_LOG_VERBOSE, "Using intra frames only.\n");
>           ctx->gop_size = 1;
> diff --git a/libavcodec/hw_base_encode.h b/libavcodec/hw_base_encode.h
> index e30b1e60ad..e768579722 100644
> --- a/libavcodec/hw_base_encode.h
> +++ b/libavcodec/hw_base_encode.h
> @@ -193,6 +193,10 @@ typedef struct FFHWBaseEncodeContext {
>       int end_of_stream;
>       int p_to_gpb;
>   
> +    // The number of L0/L1 references supported by the driver.
> +    int             ref_l0;
> +    int             ref_l1;
> +
>       // Whether the driver supports ROI at all.
>       int             roi_allowed;
>   

Looks fine, I'll push this soon.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_0xA2FEA5F03F034464.asc
Type: application/pgp-keys
Size: 624 bytes
Desc: OpenPGP public key
URL: <https://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20241222/3a376951/attachment.key>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: OpenPGP_signature.asc
Type: application/pgp-signature
Size: 236 bytes
Desc: OpenPGP digital signature
URL: <https://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20241222/3a376951/attachment.sig>