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.
> 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?
> +
> + 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.
> +
> + 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.
> + 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.
> + /* 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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