[FFmpeg-devel] [PATCH] examples/vaapi_encode: Add a VA-API encode example.

Mark Thompson sw at jkqxz.net
Thu Nov 9 23:13:50 EET 2017


On 06/11/17 06:56, Jun Zhao wrote:
> From d16f766363d9ecc240b0f8e025c2a8f91ea4775e Mon Sep 17 00:00:00 2001
> From: Jun Zhao <jun.zhao at intel.com>
> Date: Mon, 6 Nov 2017 14:45:27 +0800
> Subject: [PATCH] examples/vaapi_encode: Add a VA-API encode example.
> 
> add a VA-API encode example, only support NV12 input, usage like:
> ./vaapi_encode 1920 1080 test.yuv test.h264
> 
> Signed-off-by: Jun Zhao <jun.zhao at intel.com>
> Signed-off-by: Liu, Kaixuan <kaixuan.liu at intel.com>
> ---
>  configure                   |   2 +
>  doc/examples/Makefile       |   1 +
>  doc/examples/vaapi_encode.c | 308 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 311 insertions(+)
>  create mode 100644 doc/examples/vaapi_encode.c
> 
> diff --git a/configure b/configure
> index 1b0f064607..2df0205e09 100755
> --- a/configure
> +++ b/configure
> @@ -1524,6 +1524,7 @@ EXAMPLE_LIST="
>      scaling_video_example
>      transcode_aac_example
>      transcoding_example
> +    vaapi_encode_example
>  "
>  
>  EXTERNAL_AUTODETECT_LIBRARY_LIST="
> @@ -3294,6 +3295,7 @@ resampling_audio_example_deps="avutil swresample"
>  scaling_video_example_deps="avutil swscale"
>  transcode_aac_example_deps="avcodec avformat swresample"
>  transcoding_example_deps="avfilter avcodec avformat avutil"
> +vaapi_encode_example_deps="avfilter avcodec avformat avutil"
>  
>  # EXTRALIBS_LIST
>  cpu_init_extralibs="pthreads_extralibs"
> diff --git a/doc/examples/Makefile b/doc/examples/Makefile
> index 58afd71b85..da5af36532 100644
> --- a/doc/examples/Makefile
> +++ b/doc/examples/Makefile
> @@ -19,6 +19,7 @@ EXAMPLES-$(CONFIG_RESAMPLING_AUDIO_EXAMPLE)  += resampling_audio
>  EXAMPLES-$(CONFIG_SCALING_VIDEO_EXAMPLE)     += scaling_video
>  EXAMPLES-$(CONFIG_TRANSCODE_AAC_EXAMPLE)     += transcode_aac
>  EXAMPLES-$(CONFIG_TRANSCODING_EXAMPLE)       += transcoding
> +EXAMPLES-$(CONFIG_VAAPI_ENCODE_EXAMPLE)      += vaapi_encode
>  
>  EXAMPLES       := $(EXAMPLES-yes:%=doc/examples/%$(PROGSSUF)$(EXESUF))
>  EXAMPLES_G     := $(EXAMPLES-yes:%=doc/examples/%$(PROGSSUF)_g$(EXESUF))
> diff --git a/doc/examples/vaapi_encode.c b/doc/examples/vaapi_encode.c
> new file mode 100644
> index 0000000000..02b1ac5a4a
> --- /dev/null
> +++ b/doc/examples/vaapi_encode.c
> @@ -0,0 +1,308 @@
> +/*
> + * 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_encode.c
> + * This example shows how to do VAAPI-accelerated encoding. now only support NV12
> + * raw file, usage like: vaapi_enc 1920 1080 input.yuv output.h264
> + */
> +
> +#include <stdio.h>
> +#include <string.h>
> +#include <errno.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;
> +    const 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. Error code:%s\n", av_err2str(ret));
> +        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. Error code:%s\n", av_err2str(ret));
> +        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) {
> +        av_log(NULL, AV_LOG_ERROR, "Error code: %s\n", av_err2str(ret));
> +        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) {
> +        av_log(NULL, AV_LOG_ERROR, "Fail to config filter graph. Error code: %s\n", av_err2str(ret));
> +        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;
> +}

Do you really want to use libavfilter here for the upload?  Given that you require NV12 input, this could be done more easily by making a new hwframe context and transfering data to that.

> +
> +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) {
> +        fprintf(stderr, "Error code: %s\n", av_err2str(ret));
> +        goto end;
> +    }
> +    while (1) {
> +        ret = avcodec_receive_packet(avctx, &enc_pkt);
> +        if (ret)
> +            break;
> +
> +        enc_pkt.stream_index = 0;
> +        ret = fwrite(enc_pkt.data, enc_pkt.size, 1, fout);

For an example, I think it would be better not to rely on the implicit av_packet_unref() in avcodec_receive_packet().

> +    }
> +
> +end:
> +    ret = ((ret == AVERROR(EAGAIN)) ? 0 : -1);
> +    return ret;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +    int ret, size;
> +    FILE *fin = NULL, *fout = NULL;
> +    AVFrame *sw_frame = NULL, *hw_frame = NULL;
> +    AVCodecContext *avctx = NULL;
> +    FilterContext *filter_ctx = NULL;
> +    AVCodec *codec = NULL;
> +    const char *enc_name = "h264_vaapi";
> +    char args[512];
> +
> +    if (argc < 4) {

< 5

> +        fprintf(stderr, "Usage: %s <width> <height> <input file> <output file>\n", argv[0]);
> +        return -1;
> +    }
> +
> +    width  = atoi(argv[1]);
> +    height = atoi(argv[2]);
> +    size   = width * height;
> +
> +    if (!(fin = fopen(argv[3], "r"))) {
> +        fprintf(stderr, "Fail to open input file : %s\n", strerror(errno));
> +        ret = -1;
> +        goto close;
> +    }
> +    if (!(fout = fopen(argv[4], "w+b"))) {
> +        fprintf(stderr, "Fail to open output file : %s\n", strerror(errno));
> +        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. Error code: %s\n", av_err2str(ret));
> +        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->framerate = (AVRational){25, 1};
> +    avctx->sample_aspect_ratio = (AVRational){1, 1};
> +    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);
> +
> +    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));
> +    if (!avctx->hw_frames_ctx) {
> +        ret = AVERROR(ENOMEM);
> +        goto close;
> +    }
> +
> +    if ((ret = avcodec_open2(avctx, codec, NULL)) < 0) {
> +        fprintf(stderr, "Cannot open video encoder codec. Error code: %s\n", av_err2str(ret));
> +        goto close;
> +    }
> +
> +    while (1) {
> +        if (!(sw_frame = av_frame_alloc())) {
> +            ret = AVERROR(ENOMEM);
> +            goto close;
> +        }
> +        sw_frame->width  = width;
> +        sw_frame->height = height;
> +        sw_frame->format = AV_PIX_FMT_NV12;
> +        if ((ret = av_frame_get_buffer(sw_frame, 32)) < 0)
> +            goto close;
> +        if ((ret = fread((uint8_t*)(sw_frame->data[0]), size, 1, fin)) <= 0)
> +            break;
> +        if ((ret = fread((uint8_t*)(sw_frame->data[1]), size/2, 1, fin)) <= 0)
> +            break;
> +        /* 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. Error code: %s\n", av_err2str(ret));
> +            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;
> +            }
> +
> +            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:
> +    if (fin)
> +        fclose(fin);
> +    if (fout)
> +        fclose(fout);
> +    if (sw_frame)
> +        av_frame_free(&sw_frame);
> +    if (hw_frame)
> +        av_frame_free(&hw_frame);
> +    if (avctx)
> +        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);
> +    }
> +    if (hw_device_ctx)
> +        av_buffer_unref(&hw_device_ctx);

These free functions don't require a check - they accept and do nothing with a null pointer.

> +
> +    return ret;

This ends up returning -1 from the program when everything worked, which is a bit odd.

> +}
> -- 
> 2.14.1
> 


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