[FFmpeg-devel] [PATCH] avcodec/libvpxenc: add VP8 support for ROI-based encoding
Guo, Yejun
yejun.guo at intel.com
Wed Feb 27 10:27:00 EET 2019
> -----Original Message-----
> From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On Behalf
> Of Guo, Yejun
> Sent: Thursday, February 28, 2019 12:13 AM
> To: ffmpeg-devel at ffmpeg.org
> Subject: [FFmpeg-devel] [PATCH] avcodec/libvpxenc: add VP8 support for
> ROI-based encoding
>
> Signed-off-by: Guo, Yejun <yejun.guo at intel.com>
> ---
> libavcodec/libvpxenc.c | 132
> +++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 132 insertions(+)
>
> diff --git a/libavcodec/libvpxenc.c b/libavcodec/libvpxenc.c
> index c823b8a..e3de547 100644
> --- a/libavcodec/libvpxenc.c
> +++ b/libavcodec/libvpxenc.c
> @@ -1057,6 +1057,135 @@ 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
> +
> + AVRegionOfInterest *roi = NULL;
> + vpx_roi_map_t roi_map;
> + 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 };
> + int segment_id;
> + int zero_delta_q = 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};
> +
> + active_map.rows = (frame->height + 15) / 16;
> + active_map.cols = (frame->width + 15) / 16;
> +
> + if (!sd) {
> + 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;
> + }
> +
> + 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 (%d bytes) failed.\n",
> + active_map.rows * active_map.cols);
> + return AVERROR(ENOMEM);
> + }
> + memset(active_map.active_map, 1, active_map.rows * active_map.cols);
> +
> + /* 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_id = 0;
> + segment_mapping[zero_delta_q + MAX_DELTA_Q] = segment_id + 1;
> + segment_id++;
> + memset(&roi_map, 0, sizeof(roi_map));
> + roi_map.delta_q[segment_id] = zero_delta_q;
> +
> + 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_free(active_map.active_map);
> + av_log(avctx, AV_LOG_ERROR,
> + "roi_map alloc (%d bytes) failed.\n",
> + roi_map.rows * roi_map.cols);
> + return AVERROR(ENOMEM);
> + }
> +
> + roi = (AVRegionOfInterest*)sd->data;
> + while ((uint8_t*)roi < sd->data + sd->size) {
> + int qoffset;
> + int mapping_index;
> + int mapping_value;
> + int starty = FFMIN(roi_map.rows, roi->top / 16);
> + int endy = FFMIN(roi_map.rows, (roi->bottom + 15) / 16);
> + int startx = FFMIN(roi_map.cols, roi->left / 16);
> + int endx = FFMIN(roi_map.cols, (roi->right + 15) / 16);
> +
> + if (roi->self_size == 0) {
> + av_free(active_map.active_map);
> + av_free(roi_map.roi_map);
> + av_log(ctx, AV_LOG_ERROR, "AVRegionOfInterest.self_size must be
> set to sizeof(AVRegionOfInterest).\n");
> + return AVERROR(EINVAL);
> + }
> +
> + if (roi->qoffset.den == 0) {
> + av_free(active_map.active_map);
> + av_free(roi_map.roi_map);
> + av_log(ctx, AV_LOG_ERROR, "AVRegionOfInterest.qoffset.den must
> not be zero.\n");
> + return AVERROR(EINVAL);
> + }
> +
> + 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 > 3) {
> + av_log(ctx, AV_LOG_WARNING,
> + "ROI only support 4 segments (and segment 0 is reserved for
> non-ROIs), skipping this one.\n");
> + roi = (AVRegionOfInterest*)((char*)roi + roi->self_size);
> + continue;
> + }
> +
> + segment_mapping[mapping_index] = segment_id + 1;
> + roi_map.delta_q[segment_id] = qoffset;
> + segment_id++;
> + }
> +
> + mapping_value = segment_mapping[mapping_index];
> +
> + 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;
> +
> + roi = (AVRegionOfInterest*)((char*)roi + roi->self_size);
> + }
> +
> + if (vpx_codec_control(&ctx->encoder, VP8E_SET_ROI_MAP, &roi_map))
> {
> + av_free(active_map.active_map);
> + av_free(roi_map.roi_map);
> + log_encoder_error(avctx, "Failed to set VP8E_SET_ROI_MAP codec
> control.\n");
> + return AVERROR_INVALIDDATA;
> + }
> +
> + if (vpx_codec_control(&ctx->encoder, VP8E_SET_ACTIVEMAP,
> &active_map)) {
> + av_free(active_map.active_map);
> + av_free(roi_map.roi_map);
> + log_encoder_error(avctx, "Failed to set VP8E_SET_ACTIVEMAP codec
> control.\n");
> + return AVERROR_INVALIDDATA;
> + }
> +
> + av_free(active_map.active_map);
> + av_free(roi_map.roi_map);
> +
> + return 0;
> +}
> +
> static int vpx_encode(AVCodecContext *avctx, AVPacket *pkt,
> const AVFrame *frame, int *got_packet)
> {
> @@ -1113,6 +1242,9 @@ 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,
to verify this patch, please cherry-pick https://github.com/guoyejun/ffmpeg/commit/7ba191ad7da5cfd1e6241d0a549c3c6b88c6b2f8,
and run command like:
./ffmpeg -i .../path_to_1920x1080_video_file -vf scale=1920:1080 -c:v libvpx -b:v 5M -y tmp.webm
btw, I plan to add an example under doc/examples/ for the ROI encoding together with an object detection filter for ffmpeg. It's my next task to do.
> --
> 2.7.4
>
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