[FFmpeg-devel] [PATCH] avcodec/libvpxenc: add VP8 support for ROI-based encoding
Gyan
ffmpeg at gyani.pro
Wed Feb 27 12:22:52 EET 2019
On 27-02-2019 01:57 PM, Guo, Yejun wrote:
>
>> -----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
>
Looks like, at present, the only way to effect ROI is via side data, and
no filter or other in-tree mechanism at present can convey or generate it.
Are there any near-term plans to add some? If not, may I suggest that
you add a private option for supporting encoders, for users to input ROIs?
Thanks,
Gyan
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