[FFmpeg-devel] [PATCH V3] avcodec/libvpxenc: add VP8 support for ROI-based encoding

James Zern jzern at google.com
Fri Mar 8 03:53:11 EET 2019


On Thu, Feb 28, 2019 at 11:23 PM Guo, Yejun <yejun.guo at intel.com> wrote:
>
> Signed-off-by: Guo, Yejun <yejun.guo at intel.com>
> ---
>  libavcodec/libvpxenc.c | 150 +++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 150 insertions(+)
>
> diff --git a/libavcodec/libvpxenc.c b/libavcodec/libvpxenc.c
> index c823b8a..fc9b1fd 100644
> --- a/libavcodec/libvpxenc.c
> +++ b/libavcodec/libvpxenc.c
> @@ -1057,6 +1057,153 @@ static int queue_frames(AVCodecContext *avctx, AVPacket *pkt_out)
>      return size;
>  }
>
> +static int vp8_encode_set_roi(AVCodecContext *avctx, const AVFrame *frame)
> +{
> +    /* range of vpx_roi_map_t.delta_q[i] is [-63, 63] */
> +#define MAX_DELTA_Q 63
> +
> +    const AVRegionOfInterest *roi = NULL;
> +    vpx_roi_map_t roi_map;
> +    int ret = 0;
> +    int nb_rois;
> +    AVFrameSideData *sd = av_frame_get_side_data(frame, AV_FRAME_DATA_REGIONS_OF_INTEREST);
> +    VPxContext *ctx = avctx->priv_data;
> +    vpx_active_map_t active_map = { 0, 0, 0 };

{ 0 } will work.

> +    int max_segment_cnt = 4;    /* VP8 ROI only support 4 segments. */
> +    int segment_id = 0;
> +
> +    /* record the mapping from delta_q to "segment id + 1".
> +     * delta_q is shift with MAX_DELTA_Q, and so the range is [0, 2*MAX_DELTA_Q].
> +     * add 1 to segment id, so no mapping if the value of array element is zero.
> +     */
> +    int segment_mapping[2 * MAX_DELTA_Q + 1] = {0};
> +

{ 0 } would be more consistent with this file.

> +    /* segment id 0 in roi_map is reserved for the areas not covered by AVRegionOfInterest.
> +     * segment id 0 in roi_map is also for the areas with AVRegionOfInterest.qoffset near 0.
> +     */
> +    segment_mapping[MAX_DELTA_Q] = segment_id + 1;
> +    segment_id++;
> +
> +    active_map.rows = (frame->height + 15) / 16;
> +    active_map.cols = (frame->width  + 15) / 16;
> +
> +    if (!sd) {
> +        /* For the case that some middle frames do not have ROI while other frames have ROIs.
> +         * Due to libvpx behaivor, we have to reset VP8E_SET_ACTIVEMAP, otherwise the previous

behavior

> +         * ROIs continue working for frames without ROIs.
> +         */
> +        if (vpx_codec_control(&ctx->encoder, VP8E_SET_ACTIVEMAP, &active_map)) {
> +            log_encoder_error(avctx, "Failed to set VP8E_SET_ACTIVEMAP codec control.\n");
> +            return AVERROR_INVALIDDATA;
> +        }
> +        return 0;
> +    }
> +
> +    memset(&roi_map, 0, sizeof(roi_map));
> +    roi_map.rows = active_map.rows;
> +    roi_map.cols = active_map.cols;
> +    roi_map.roi_map = av_mallocz(roi_map.rows * roi_map.cols);
> +    if (!roi_map.roi_map) {
> +        av_log(avctx, AV_LOG_ERROR, "roi_map alloc failed.\n");
> +        ret = AVERROR(ENOMEM);
> +        goto fail;
> +    }
> +
> +    active_map.active_map = av_malloc(active_map.rows * active_map.cols);
> +    if (!active_map.active_map) {
> +        av_log(avctx, AV_LOG_ERROR, "active_map alloc failed.\n");
> +        ret = AVERROR(ENOMEM);
> +        goto fail;
> +    }
> +    /* set 1 to enable the corresponding element of vpx_roi_map_t.roi_map. */
> +    memset(active_map.active_map, 1, active_map.rows * active_map.cols);
> +
> +    roi = (const AVRegionOfInterest*)sd->data;
> +    if (!roi->self_size || sd->size % roi->self_size != 0) {
> +        av_log(ctx, AV_LOG_ERROR, "Invalid AVRegionOfInterest.self_size.\n");
> +        ret = AVERROR(EINVAL);
> +        goto fail;
> +    }
> +    nb_rois = sd->size / roi->self_size;
> +
> +    /* This list must be iterated from zero because regions are
> +     * defined in order of decreasing importance. So discard less
> +     * important areas if exceeding the supported segment count.

...if they exceed the segment count

> +     */
> +    for (int i = 0; i < nb_rois; i++) {
> +        int qoffset;
> +        int mapping_index;
> +
> +        roi = (const AVRegionOfInterest*)(sd->data + roi->self_size * i);
> +        if (roi->qoffset.den == 0) {
> +            av_log(ctx, AV_LOG_ERROR, "AVRegionOfInterest.qoffset.den must not be zero.\n");
> +            ret = AVERROR(EINVAL);
> +            goto fail;
> +        }
> +
> +        qoffset = (int)(roi->qoffset.num * 1.0f / roi->qoffset.den * MAX_DELTA_Q);
> +        qoffset = av_clip(qoffset, -MAX_DELTA_Q, MAX_DELTA_Q);
> +
> +        mapping_index = qoffset + MAX_DELTA_Q;
> +        if (!segment_mapping[mapping_index]) {
> +            if (segment_id > max_segment_cnt - 1) {
> +                av_log(ctx, AV_LOG_WARNING,
> +                       "ROI only support %d segments (and segment 0 is reserved for non-ROIs), skipping this one.\n",

supports

> +                       max_segment_cnt);
> +                roi = (AVRegionOfInterest*)((char*)roi + roi->self_size);
> +                continue;
> +            }
> +
> +            segment_mapping[mapping_index] = segment_id + 1;
> +            roi_map.delta_q[segment_id] = qoffset;
> +            segment_id++;
> +        }
> +    }
> +
> +    /* This list must be iterated in reverse, so for the case that
> +     * two regions overlapping, the more important area takes effect.
> +     */
> +    for (int i = nb_rois - 1; i >= 0; i--) {
> +        int qoffset;
> +        int mapping_value;
> +        int starty, endy, startx, endx;
> +
> +        roi = (const AVRegionOfInterest*)(sd->data + roi->self_size * i);
> +
> +        starty = FFMIN(roi_map.rows, roi->top / 16);
> +        endy   = FFMIN(roi_map.rows, (roi->bottom + 15) / 16);
> +        startx = FFMIN(roi_map.cols, roi->left / 16);
> +        endx   = FFMIN(roi_map.cols, (roi->right + 15) / 16);
> +
> +        qoffset = (int)(roi->qoffset.num * 1.0f / roi->qoffset.den * MAX_DELTA_Q);
> +        qoffset = av_clip(qoffset, -MAX_DELTA_Q, MAX_DELTA_Q);
> +
> +        mapping_value = segment_mapping[qoffset + MAX_DELTA_Q];
> +        if (mapping_value) {
> +            for (int y = starty; y < endy; y++)
> +                for (int x = startx; x < endx; x++)
> +                    roi_map.roi_map[x + y * roi_map.cols] = mapping_value - 1;
> +        }
> +    }
> +
> +    if (vpx_codec_control(&ctx->encoder, VP8E_SET_ROI_MAP, &roi_map)) {
> +        log_encoder_error(avctx, "Failed to set VP8E_SET_ROI_MAP codec control.\n");
> +        ret = AVERROR_INVALIDDATA;
> +        goto fail;
> +    }
> +
> +    if (vpx_codec_control(&ctx->encoder, VP8E_SET_ACTIVEMAP, &active_map)) {
> +        log_encoder_error(avctx, "Failed to set VP8E_SET_ACTIVEMAP codec control.\n");
> +        ret = AVERROR_INVALIDDATA;
> +        goto fail;
> +    }
> +
> +fail:
> +    av_freep(&active_map.active_map);
> +    av_freep(&roi_map.roi_map);
> +    return ret;
> +}
> +
>  static int vpx_encode(AVCodecContext *avctx, AVPacket *pkt,
>                        const AVFrame *frame, int *got_packet)
>  {
> @@ -1113,6 +1260,9 @@ static int vpx_encode(AVCodecContext *avctx, AVPacket *pkt,
>                  flags |= strtoul(en->value, NULL, 10);
>              }
>          }
> +
> +        if (avctx->codec_id == AV_CODEC_ID_VP8)
> +            vp8_encode_set_roi(avctx, frame);
>      }
>
>      res = vpx_codec_encode(&ctx->encoder, rawimg, timestamp,
> --
> 2.7.4
>
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