On 2017/7/30 8:07, Mark Thompson wrote:
> On 28/07/17 07:01, Jun Zhao wrote:
>> From d5414b451012b3a0169740a26f452785eb44cce5 Mon Sep 17 00:00:00 2001
>> From: Jun Zhao <jun.z...@intel.com>
>> Date: Fri, 28 Jul 2017 01:39:27 -0400
>> Subject: [PATCH] examples/vaapi_enc: Add a VAAPI encoding example.
>>
>> Add a VAAPI encoding example.
>>
>> Use hwupload loading the raw date in HW surface, usage
>> like this: ./vaapi_enc 1920 1080 input.yuv test.h264
>>
>> Signed-off-by: Liu, Kaixuan <kaixuan....@intel.com>
>> Signed-off-by: Jun Zhao <jun.z...@intel.com>
>> ---
>> doc/examples/vaapi_enc.c | 291
>> +++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 291 insertions(+)
>> create mode 100644 doc/examples/vaapi_enc.c
>
> A general thought: do you actually want to use lavfi here? All it's really
> doing is the hw frame creation and upload, which would be shorter to
> implement directly (av_hwframe_ctx_create(), av_hwframe_ctx_init(),
> av_hwframe_transfer_data()). If the example might be extended with more
> stuff going on in filters then obviously the lavfi stuff is needed, but it
> seems overcomplicated if the intent is just to demonstrate encode.
As the API view, I don't want to use lavfi for VAAPI NEC example, I prefer
a simple API or simple step than use lavfi to load YUV from CPU to GPU surface,
Can we give a simple API or step to load YUV to HW surface in this case ? even
use
av_hwframe_xxx interface, it's not a easy task for the caller.
>
>
>> diff --git a/doc/examples/vaapi_enc.c b/doc/examples/vaapi_enc.c
>> new file mode 100644
>> index 0000000000..e26db0e343
>> --- /dev/null
>> +++ b/doc/examples/vaapi_enc.c
>> @@ -0,0 +1,291 @@
>> +/*
>> + * Video Acceleration API (video encoding) encode sample
>> + *
>> + * This file is part of FFmpeg.
>> + *
>> + * FFmpeg is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU Lesser General Public
>> + * License as published by the Free Software Foundation; either
>> + * version 2.1 of the License, or (at your option) any later version.
>> + *
>> + * FFmpeg is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>> + * Lesser General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU Lesser General Public
>> + * License along with FFmpeg; if not, write to the Free Software
>> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
>> USA
>> + */
>> +
>> +/**
>> + * @file
>> + * Intel VAAPI-accelerated encoding example.
>> + *
>> + * @example vaapi_enc.c
>> + * This example shows how to do VAAPI-accelerated encoding. now only
>> support NV12
>> + * raw file, usage: vaapi_enc 1920 1080 input.yuv output.h264
>> + */
>> +
>> +#include <stdio.h>
>> +#include <string.h>
>> +
>> +#include <libavcodec/avcodec.h>
>> +#include <libavformat/avformat.h>
>> +#include <libavfilter/avfiltergraph.h>
>> +#include <libavfilter/buffersink.h>
>> +#include <libavfilter/buffersrc.h>
>> +#include <libavutil/pixdesc.h>
>> +#include <libavutil/hwcontext.h>
>> +
>> +typedef struct FilterContext {
>> + AVFilterContext *buffersink_ctx;
>> + AVFilterContext *buffersrc_ctx;
>> + AVFilterGraph *filter_graph;
>> +} FilterContext;
>> +
>> +static int width, height;
>> +static AVBufferRef *hw_device_ctx = NULL;
>> +
>> +static int
>> +init_filter(FilterContext *filter_ctx, char *args, AVBufferRef
>> *hw_device_ctx)
>> +{
>> + char filter_spec[] = "format=nv12,hwupload";
>> + int ret = 0, i = 0;
>> + AVFilter *buffersrc, *buffersink;
>> + AVFilterContext *buffersrc_ctx, *buffersink_ctx;
>> + AVFilterInOut *outputs = avfilter_inout_alloc();
>> + AVFilterInOut *inputs = avfilter_inout_alloc();
>> + AVFilterGraph *filter_graph = avfilter_graph_alloc();
>> +
>> + buffersrc = avfilter_get_by_name("buffer");
>> + buffersink = avfilter_get_by_name("buffersink");
>> + if (!buffersrc || !buffersink) {
>> + av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not
>> found\n");
>> + ret = AVERROR_UNKNOWN;
>> + goto fail;
>> + }
>> +
>> + ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
>> + args, NULL, filter_graph);
>> + if (ret < 0) {
>> + av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n");
>> + goto fail;
>> + }
>> + ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
>> + NULL, NULL, filter_graph);
>> + if (ret < 0) {
>> + av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink.\n");
>> + goto fail;
>> + }
>> +
>> + outputs->name = av_strdup("in");
>> + outputs->filter_ctx = buffersrc_ctx;
>> + outputs->pad_idx = 0;
>> + outputs->next = NULL;
>> + inputs->name = av_strdup("out");
>> + inputs->filter_ctx = buffersink_ctx;
>> + inputs->pad_idx = 0;
>> + inputs->next = NULL;
>> + if (!outputs->name || !inputs->name) {
>> + ret = AVERROR(ENOMEM);
>> + goto fail;
>> + }
>> +
>> + if ((ret = avfilter_graph_parse_ptr(filter_graph, filter_spec,
>> + &inputs, &outputs, NULL)) < 0)
>> + goto fail;
>> + if (hw_device_ctx) {
>> + for (i = 0; i < filter_graph->nb_filters; i++) {
>> + filter_graph->filters[i]->hw_device_ctx =
>> av_buffer_ref(hw_device_ctx);
>> + }
>> + }
>> +
>> + if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
>> + goto fail;
>> +
>> + filter_ctx->buffersrc_ctx = buffersrc_ctx;
>> + filter_ctx->buffersink_ctx = buffersink_ctx;
>> + filter_ctx->filter_graph = filter_graph;
>> +
>> +fail:
>> + avfilter_inout_free(&inputs);
>> + avfilter_inout_free(&outputs);
>> + return ret;
>> +}
>> +
>> +static int encode_write(AVCodecContext *avctx, AVFrame *frame, FILE *fout)
>> +{
>> + int ret = 0;
>> + AVPacket enc_pkt;
>> +
>> + av_init_packet(&enc_pkt);
>> + enc_pkt.data = NULL;
>> + enc_pkt.size = 0;
>> +
>> + if ((ret = avcodec_send_frame(avctx, frame)) < 0)
>> + goto end;
>> + while (1) {
>> + ret = avcodec_receive_packet(avctx, &enc_pkt);
>> + if (!ret) {
>> + enc_pkt.stream_index = 0;
>> + ret = fwrite(enc_pkt.data, enc_pkt.size, 1, fout);
>> + } else {
>> + break;
>> + }
>> + }
>> +
>> +end:
>> + ret = ((ret == AVERROR(EAGAIN)) ? 0 : -1);
>> + return ret;
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + int ret, size;
>> + FILE *fin, *fout;
>> + AVFrame *sw_frame, *hw_frame;
>> + AVCodecContext *avctx = NULL;
>> + FilterContext *filter_ctx;
>> + AVCodec *codec = NULL;
>> + uint8_t *frame_buf;
>> + const char *input_file, *output_file;
>> + const char *enc_name = "h264_vaapi";
>> + char args[512];
>> + int count = 0;
>
> Print a usage line here if there aren't the expected number of arguments?
OK
>
>> +
>> + width = atoi(argv[1]);
>> + height = atoi(argv[2]);
>> + input_file = argv[3];
>> + output_file = argv[4];
>> +
>> + size = width * height;
>> + frame_buf = malloc((size * 3) / 2); /* size for nv12 frame */
>> + fin = fopen(input_file, "r");
>> + fout = fopen(output_file, "w+b");
>> + if (!fin || !fout) {
>> + fprintf(stderr, "Fail to open input or output file.\n");
>> + ret = -1;
>> + goto close;
>> + }
>> +
>> + av_register_all();
>> + avfilter_register_all();
>> +
>> + ret = av_hwdevice_ctx_create(&hw_device_ctx, AV_HWDEVICE_TYPE_VAAPI,
>> + NULL, NULL, 0);
>> + if (ret < 0) {
>> + fprintf(stderr, "Failed to create a VAAPI device.\n");
>> + goto close;
>> + }
>> +
>> + if (!(codec = avcodec_find_encoder_by_name(enc_name))) {
>> + fprintf(stderr, "Could not find encoder.\n");
>> + ret = -1;
>> + goto close;
>> + }
>> +
>> + if (!(avctx = avcodec_alloc_context3(codec))) {
>> + ret = AVERROR(ENOMEM);
>> + goto close;
>> + }
>> +
>> + avctx->width = width;
>> + avctx->height = height;
>> + avctx->time_base = (AVRational){1, 25};
>> + avctx->pix_fmt = AV_PIX_FMT_VAAPI;
>> +
>> + /* create filters and binding HWDevice */
>> + snprintf(args, sizeof(args),
>> +
>> "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d:frame_rate=%d/%d",
>> + avctx->width, avctx->height, AV_PIX_FMT_NV12,
>> + avctx->time_base.num, avctx->time_base.den,
>> + avctx->sample_aspect_ratio.num, avctx->sample_aspect_ratio.den,
>> + avctx->framerate.num, avctx->framerate.den);
>
> SAR and framerate aren't initialised? SAR probably doesn't matter, but I
> think framerate wants to be 1/time_base here to make it clearly CFR. Also,
> since it does end up in the output stream, having it be configurable as
> another command-line option might be nice.
Will double-check this part.
>
>> +
>> + if (!(filter_ctx = av_malloc(sizeof(*filter_ctx)))) {
>> + ret = AVERROR(ENOMEM);
>> + goto close;
>> + }
>> +
>> + if ((ret = init_filter(filter_ctx, args, hw_device_ctx)) < 0) {
>> + fprintf(stderr, "Failed to initialize the filtering context.\n");
>> + goto close;
>> + }
>> +
>> + avctx->hw_frames_ctx = av_buffer_ref(av_buffersink_get_hw_frames_ctx
>> + (filter_ctx->buffersink_ctx));
>
> Can fail.
Will add error handle
>
>> + if ((ret = avcodec_open2(avctx, codec, NULL)) < 0)
>> + fprintf(stderr, "Cannot open video encoder codec.\n");
>> +
>> + while (fread(frame_buf, (size * 3)/2, 1, fin) > 0) {
>
> Will encode a combination of old and new data on a short read.
>
>> + if (!(sw_frame = av_frame_alloc())) {
>> + ret = AVERROR(ENOMEM);
>> + goto close;
>> + }
>> + sw_frame->data[0] = frame_buf;
>> + sw_frame->data[1] = frame_buf + size;
>> + sw_frame->linesize[0] = width;
>> + sw_frame->linesize[1] = width;
>> + sw_frame->width = width;
>> + sw_frame->height = height;
>> + sw_frame->format = AV_PIX_FMT_NV12;
>
> I think it would be nicer to only use refcounted frames here. Allocate, set
> width/height/format, call av_frame_get_buffer(), then fread() into the data
> planes.
Will clean this part.
>
>> + /* push the sw frame into the filtergraph */
>> + ret = av_buffersrc_add_frame_flags(filter_ctx->buffersrc_ctx,
>> + sw_frame, 0);
>> + if (ret < 0) {
>> + fprintf(stderr, "Error while feeding the filtergraph.\n");
>> + goto close;
>> + }
>> + /* pull hw frames from the filtergraph */
>> + while (1) {
>> + if (!(hw_frame = av_frame_alloc())) {
>> + ret = AVERROR(ENOMEM);
>> + goto close;
>> + }
>> + if ((ret = (av_buffersink_get_frame(filter_ctx->buffersink_ctx,
>> hw_frame))) < 0) {
>> + /* if no more frames for output - returns AVERROR(EAGAIN)
>> + * if flushed and no more frames for output - returns
>> AVERROR_EOF
>> + * rewrite retcode to 0 to show it as normal procedure
>> completion
>> + */
>> + if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
>> + ret = 0;
>> + av_frame_free(&hw_frame);
>> + break;
>> + }
>> + count++;
>> + if (count % avctx->gop_size == 1) {
>> + hw_frame->pict_type = AV_PICTURE_TYPE_I;
>> + } else {
>> + hw_frame->pict_type = AV_PICTURE_TYPE_B;
>> + }
>
> The GOP setting is already used inside the encoder, so this won't do
> anything? Showing that pict_type can be set to generate intra frames might
> be useful for an example, but I think this needs a slightly more meaningful
> mechanism.
>
>> +
>> + if ((ret = (encode_write(avctx, hw_frame, fout))) < 0) {
>> + fprintf(stderr, "Failed to encode.\n");
>> + goto close;
>> + }
>> + av_frame_free(&hw_frame);
>> + }
>> + av_frame_free(&sw_frame);
>> + }
>> +
>> + /* flush encode */
>> + ret = encode_write(avctx, NULL, fout);
>> +
>> +close:
>> + fclose(fin);
>> + fclose(fout);
>> + av_frame_free(&sw_frame);
>> + av_frame_free(&hw_frame);
>> + avcodec_free_context(&avctx);
>> + if (filter_ctx) {
>> + avfilter_free(filter_ctx->buffersrc_ctx);
>> + avfilter_free(filter_ctx->buffersink_ctx);
>> + avfilter_graph_free(&(filter_ctx->filter_graph));
>> + av_free(filter_ctx);
>> + }
>> + av_buffer_unref(&hw_device_ctx);
>> + free(frame_buf);
>> +
>> + return ret;
>> +}
>> --
>> 2.11.0
>>
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