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

Guo, Yejun yejun.guo at intel.com
Fri Mar 8 15:04:43 EET 2019



> -----Original Message-----
> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
> Of James Zern
> Sent: Friday, March 08, 2019 9:53 AM
> To: FFmpeg development discussions and patches <ffmpeg-
> devel at ffmpeg.org>
> Subject: Re: [FFmpeg-devel] [PATCH V3] avcodec/libvpxenc: add VP8
> support for ROI-based encoding
> 
> 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.

thanks, will fix.

> 
> > +    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.

will fix

> 
> > +    /* 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

will fix

> 
> > +         * 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

will fix

> 
> > +     */
> > +    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

thanks will fix.

btw, libvpx has fixed the vp9+roi issue and they plan on making a release within the next 3-4 months.
I'll send out v4 patch for vp8 roi now, and keep an eye on the new release of libvpx.

> 
> > +                       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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> > ffmpeg-devel at ffmpeg.org
> > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
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