[FFmpeg-devel] [PATCH 6/7] libavfilter/vf_sr.c: Removes uint8 -> float and float -> uint8 conversions.
Pedro Arthur
bygrandao at gmail.com
Tue Aug 14 22:07:14 EEST 2018
2018-08-14 15:45 GMT-03:00 Rostislav Pehlivanov <atomnuker at gmail.com>:
> On Thu, 2 Aug 2018 at 20:00, Sergey Lavrushkin <dualfal at gmail.com> wrote:
>
>> This patch removes conversions, declared inside the sr filter, and uses
>> libswscale inside
>> the filter to perform them for only Y channel of input. The sr filter
>> still has uint
>> formats as input, as it does not use chroma channels in models and these
>> channels are
>> upscaled using libswscale, float formats for input would cause unnecessary
>> conversions
>> during scaling for these channels.
>>
>> ---
>> libavfilter/vf_sr.c | 134
>> +++++++++++++++++++---------------------------------
>> 1 file changed, 48 insertions(+), 86 deletions(-)
>>
>> diff --git a/libavfilter/vf_sr.c b/libavfilter/vf_sr.c
>> index 944a0e28e7..5ad1baa4c0 100644
>> --- a/libavfilter/vf_sr.c
>> +++ b/libavfilter/vf_sr.c
>> @@ -45,8 +45,8 @@ typedef struct SRContext {
>> DNNModel *model;
>> DNNData input, output;
>> int scale_factor;
>> - struct SwsContext *sws_context;
>> - int sws_slice_h;
>> + struct SwsContext *sws_contexts[3];
>> + int sws_slice_h, sws_input_linesize, sws_output_linesize;
>> } SRContext;
>>
>> #define OFFSET(x) offsetof(SRContext, x)
>> @@ -95,6 +95,10 @@ static av_cold int init(AVFilterContext *context)
>> return AVERROR(EIO);
>> }
>>
>> + sr_context->sws_contexts[0] = NULL;
>> + sr_context->sws_contexts[1] = NULL;
>> + sr_context->sws_contexts[2] = NULL;
>> +
>> return 0;
>> }
>>
>> @@ -110,6 +114,7 @@ static int query_formats(AVFilterContext *context)
>> av_log(context, AV_LOG_ERROR, "could not create formats list\n");
>> return AVERROR(ENOMEM);
>> }
>> +
>> return ff_set_common_formats(context, formats_list);
>> }
>>
>> @@ -140,21 +145,31 @@ static int config_props(AVFilterLink *inlink)
>> else{
>> outlink->h = sr_context->output.height;
>> outlink->w = sr_context->output.width;
>> + sr_context->sws_contexts[1] =
>> sws_getContext(sr_context->input.width, sr_context->input.height,
>> AV_PIX_FMT_GRAY8,
>> +
>> sr_context->input.width, sr_context->input.height, AV_PIX_FMT_GRAYF32,
>> + 0, NULL, NULL, NULL);
>> + sr_context->sws_input_linesize = sr_context->input.width << 2;
>> + sr_context->sws_contexts[2] =
>> sws_getContext(sr_context->output.width, sr_context->output.height,
>> AV_PIX_FMT_GRAYF32,
>> +
>> sr_context->output.width, sr_context->output.height, AV_PIX_FMT_GRAY8,
>> + 0, NULL, NULL, NULL);
>> + sr_context->sws_output_linesize = sr_context->output.width << 2;
>> + if (!sr_context->sws_contexts[1] || !sr_context->sws_contexts[2]){
>> + av_log(context, AV_LOG_ERROR, "could not create SwsContext
>> for conversions\n");
>> + return AVERROR(ENOMEM);
>> + }
>> switch (sr_context->model_type){
>> case SRCNN:
>> - sr_context->sws_context = sws_getContext(inlink->w,
>> inlink->h, inlink->format,
>> - outlink->w,
>> outlink->h, outlink->format, SWS_BICUBIC, NULL, NULL, NULL);
>> - if (!sr_context->sws_context){
>> - av_log(context, AV_LOG_ERROR, "could not create
>> SwsContext\n");
>> + sr_context->sws_contexts[0] = sws_getContext(inlink->w,
>> inlink->h, inlink->format,
>> + outlink->w,
>> outlink->h, outlink->format,
>> + SWS_BICUBIC,
>> NULL, NULL, NULL);
>> + if (!sr_context->sws_contexts[0]){
>> + av_log(context, AV_LOG_ERROR, "could not create
>> SwsContext for scaling\n");
>> return AVERROR(ENOMEM);
>> }
>> sr_context->sws_slice_h = inlink->h;
>> break;
>> case ESPCN:
>> - if (inlink->format == AV_PIX_FMT_GRAY8){
>> - sr_context->sws_context = NULL;
>> - }
>> - else{
>> + if (inlink->format != AV_PIX_FMT_GRAY8){
>> sws_src_h = sr_context->input.height;
>> sws_src_w = sr_context->input.width;
>> sws_dst_h = sr_context->output.height;
>> @@ -184,13 +199,14 @@ static int config_props(AVFilterLink *inlink)
>> sws_dst_w = AV_CEIL_RSHIFT(sws_dst_w, 2);
>> break;
>> default:
>> - av_log(context, AV_LOG_ERROR, "could not create
>> SwsContext for input pixel format");
>> + av_log(context, AV_LOG_ERROR, "could not create
>> SwsContext for scaling for given input pixel format");
>> return AVERROR(EIO);
>> }
>> - sr_context->sws_context = sws_getContext(sws_src_w,
>> sws_src_h, AV_PIX_FMT_GRAY8,
>> - sws_dst_w,
>> sws_dst_h, AV_PIX_FMT_GRAY8, SWS_BICUBIC, NULL, NULL, NULL);
>> - if (!sr_context->sws_context){
>> - av_log(context, AV_LOG_ERROR, "could not create
>> SwsContext\n");
>> + sr_context->sws_contexts[0] = sws_getContext(sws_src_w,
>> sws_src_h, AV_PIX_FMT_GRAY8,
>> + sws_dst_w,
>> sws_dst_h, AV_PIX_FMT_GRAY8,
>> + SWS_BICUBIC,
>> NULL, NULL, NULL);
>> + if (!sr_context->sws_contexts[0]){
>> + av_log(context, AV_LOG_ERROR, "could not create
>> SwsContext for scaling\n");
>> return AVERROR(ENOMEM);
>> }
>> sr_context->sws_slice_h = sws_src_h;
>> @@ -201,61 +217,12 @@ static int config_props(AVFilterLink *inlink)
>> }
>> }
>>
>> -typedef struct ThreadData{
>> - uint8_t *data;
>> - int data_linesize, height, width;
>> -} ThreadData;
>> -
>> -static int uint8_to_float(AVFilterContext *context, void *arg, int jobnr,
>> int nb_jobs)
>> -{
>> - SRContext *sr_context = context->priv;
>> - const ThreadData *td = arg;
>> - const int slice_start = (td->height * jobnr ) / nb_jobs;
>> - const int slice_end = (td->height * (jobnr + 1)) / nb_jobs;
>> - const uint8_t *src = td->data + slice_start * td->data_linesize;
>> - float *dst = sr_context->input.data + slice_start * td->width;
>> - int y, x;
>> -
>> - for (y = slice_start; y < slice_end; ++y){
>> - for (x = 0; x < td->width; ++x){
>> - dst[x] = (float)src[x] / 255.0f;
>> - }
>> - src += td->data_linesize;
>> - dst += td->width;
>> - }
>> -
>> - return 0;
>> -}
>> -
>> -static int float_to_uint8(AVFilterContext *context, void *arg, int jobnr,
>> int nb_jobs)
>> -{
>> - SRContext *sr_context = context->priv;
>> - const ThreadData *td = arg;
>> - const int slice_start = (td->height * jobnr ) / nb_jobs;
>> - const int slice_end = (td->height * (jobnr + 1)) / nb_jobs;
>> - const float *src = sr_context->output.data + slice_start * td->width;
>> - uint8_t *dst = td->data + slice_start * td->data_linesize;
>> - int y, x;
>> -
>> - for (y = slice_start; y < slice_end; ++y){
>> - for (x = 0; x < td->width; ++x){
>> - dst[x] = (uint8_t)(255.0f * FFMIN(src[x], 1.0f));
>> - }
>> - src += td->width;
>> - dst += td->data_linesize;
>> - }
>> -
>> - return 0;
>> -}
>> -
>> static int filter_frame(AVFilterLink *inlink, AVFrame *in)
>> {
>> AVFilterContext *context = inlink->dst;
>> SRContext *sr_context = context->priv;
>> AVFilterLink *outlink = context->outputs[0];
>> AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
>> - ThreadData td;
>> - int nb_threads;
>> DNNReturnType dnn_result;
>>
>> if (!out){
>> @@ -268,28 +235,23 @@ static int filter_frame(AVFilterLink *inlink,
>> AVFrame *in)
>> out->width = sr_context->output.width;
>> switch (sr_context->model_type){
>> case SRCNN:
>> - sws_scale(sr_context->sws_context, (const uint8_t **)in->data,
>> in->linesize,
>> + sws_scale(sr_context->sws_contexts[0], (const uint8_t
>> **)in->data, in->linesize,
>> 0, sr_context->sws_slice_h, out->data, out->linesize);
>> - td.data = out->data[0];
>> - td.data_linesize = out->linesize[0];
>> - td.height = out->height;
>> - td.width = out->width;
>> +
>> + sws_scale(sr_context->sws_contexts[1], (const uint8_t
>> **)out->data, out->linesize,
>> + 0, out->height, (uint8_t *
>> const*)(&sr_context->input.data), &sr_context->sws_input_linesize);
>> break;
>> case ESPCN:
>> - if (sr_context->sws_context){
>> - sws_scale(sr_context->sws_context, (const uint8_t
>> **)(in->data + 1), in->linesize + 1,
>> + if (sr_context->sws_contexts[0]){
>> + sws_scale(sr_context->sws_contexts[0], (const uint8_t
>> **)(in->data + 1), in->linesize + 1,
>> 0, sr_context->sws_slice_h, out->data + 1,
>> out->linesize + 1);
>> - sws_scale(sr_context->sws_context, (const uint8_t
>> **)(in->data + 2), in->linesize + 2,
>> + sws_scale(sr_context->sws_contexts[0], (const uint8_t
>> **)(in->data + 2), in->linesize + 2,
>> 0, sr_context->sws_slice_h, out->data + 2,
>> out->linesize + 2);
>> }
>> - td.data = in->data[0];
>> - td.data_linesize = in->linesize[0];
>> - td.height = in->height;
>> - td.width = in->width;
>> - }
>>
>> - nb_threads = ff_filter_get_nb_threads(context);
>> - context->internal->execute(context, uint8_to_float, &td, NULL,
>> FFMIN(td.height, nb_threads));
>> + sws_scale(sr_context->sws_contexts[1], (const uint8_t
>> **)in->data, in->linesize,
>> + 0, in->height, (uint8_t *
>> const*)(&sr_context->input.data), &sr_context->sws_input_linesize);
>> + }
>> av_frame_free(&in);
>>
>> dnn_result =
>> (sr_context->dnn_module->execute_model)(sr_context->model);
>> @@ -298,17 +260,15 @@ static int filter_frame(AVFilterLink *inlink,
>> AVFrame *in)
>> return AVERROR(EIO);
>> }
>>
>> - td.data = out->data[0];
>> - td.data_linesize = out->linesize[0];
>> - td.height = out->height;
>> - td.width = out->width;
>> - context->internal->execute(context, float_to_uint8, &td, NULL,
>> FFMIN(td.height, nb_threads));
>> + sws_scale(sr_context->sws_contexts[2], (const uint8_t
>> **)(&sr_context->output.data), &sr_context->sws_output_linesize,
>> + 0, out->height, (uint8_t * const*)out->data, out->linesize);
>>
>> return ff_filter_frame(outlink, out);
>> }
>>
>> static av_cold void uninit(AVFilterContext *context)
>> {
>> + int i;
>> SRContext *sr_context = context->priv;
>>
>> if (sr_context->dnn_module){
>> @@ -316,8 +276,10 @@ static av_cold void uninit(AVFilterContext *context)
>> av_freep(&sr_context->dnn_module);
>> }
>>
>> - if (sr_context->sws_context){
>> - sws_freeContext(sr_context->sws_context);
>> + for (i = 0; i < 3; ++i){
>> + if (sr_context->sws_contexts[i]){
>> + sws_freeContext(sr_context->sws_contexts[i]);
>> + }
>> }
>> }
>>
>> --
>> 2.14.1
>>
>> _______________________________________________
>> ffmpeg-devel mailing list
>> ffmpeg-devel at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
>
> You are planning to remove *all* conversion still, right? Its still
> unacceptable that there *are* conversions.
They are here because it is the most efficient way to do it. The
filter works only on luminance channel therefore we only apply
conversion to Y channel, and bicubic upscale to chrominance.
I can't see how one can achieve the same result, without doing useless
computations, if not in this way.
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