[FFmpeg-devel] [PATCH] examples/vaapi_dec_scaling: init export

mypopy at gmail.com mypopy at gmail.com
Tue Aug 21 05:45:47 EEST 2018


On Mon, Jun 11, 2018 at 7:22 PM Jun Zhao <mypopydev at gmail.com> wrote:
>
> add a vaapi decoding/scaling sample.
>
> Signed-off-by: Jun Zhao <mypopydev at gmail.com>
> ---
>  configure                        |   2 +
>  doc/examples/Makefile            |   1 +
>  doc/examples/vaapi_dec_scaling.c | 375
+++++++++++++++++++++++++++++++++++++++
>  3 files changed, 378 insertions(+)
>  create mode 100644 doc/examples/vaapi_dec_scaling.c
>
> diff --git a/configure b/configure
> index 473be31..d28dc37 100755
> --- a/configure
> +++ b/configure
> @@ -1610,6 +1610,7 @@ EXAMPLE_LIST="
>      scaling_video_example
>      transcode_aac_example
>      transcoding_example
> +    vaapi_dec_scaling_example
>      vaapi_encode_example
>      vaapi_transcode_example
>  "
> @@ -3445,6 +3446,7 @@ 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_dec_scaling_example_deps="avfilter avcodec avformat avutil"
>  vaapi_encode_example_deps="avcodec avutil h264_vaapi_encoder"
>  vaapi_transcode_example_deps="avcodec avformat avutil h264_vaapi_encoder"
>
> diff --git a/doc/examples/Makefile b/doc/examples/Makefile
> index 928ff30..3ea6899 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-$(CONFIG_VAAPI_DEC_SCALING_EXAMPLE) += vaapi_dec_scaling
>  EXAMPLES-$(CONFIG_VAAPI_ENCODE_EXAMPLE)      += vaapi_encode
>  EXAMPLES-$(CONFIG_VAAPI_TRANSCODE_EXAMPLE)   += vaapi_transcode
>
> diff --git a/doc/examples/vaapi_dec_scaling.c
b/doc/examples/vaapi_dec_scaling.c
> new file mode 100644
> index 0000000..6ec65da
> --- /dev/null
> +++ b/doc/examples/vaapi_dec_scaling.c
> @@ -0,0 +1,375 @@
> +/*
> + * Copyright (c) 2018 Jun Zhao
> + *
> + * VA-API Acceleration API (video decoding/scaling) 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
> + * VA-API-Accelerated decoding/scaling example.
> + *
> + * @example vaapi_dec_scaling.c
> + * This example shows how to do VA-API-accelerated decoding/scaling with
output
> + * frames from the HW video surfaces.
> + */
> +
> +#include <stdio.h>
> +
> +#include <libavcodec/avcodec.h>
> +#include <libavformat/avformat.h>
> +#include <libavfilter/buffersink.h>
> +#include <libavfilter/buffersrc.h>
> +#include <libavutil/pixdesc.h>
> +#include <libavutil/hwcontext.h>
> +#include <libavutil/opt.h>
> +#include <libavutil/avassert.h>
> +#include <libavutil/imgutils.h>
> +
> +static AVBufferRef *hw_device_ctx = NULL;
> +static enum AVPixelFormat hw_pix_fmt;
> +static FILE *output_file = NULL;
> +AVFilterContext *buffersink_ctx;
> +AVFilterContext *buffersrc_ctx;
> +AVFilterGraph *filter_graph;
> +const char *filter_descr =
> +    "format=vaapi,scale_vaapi=w=iw/2:h=ih/2,hwdownload,format=nv12";
> +int init_filter = 0;
> +
> +static int init_hw_decode(AVCodecContext *ctx, const enum AVHWDeviceType
type)
> +{
> +    int err = 0;
> +
> +    if ((err = av_hwdevice_ctx_create(&hw_device_ctx, type,
> +                                      NULL, NULL, 0)) < 0) {
> +        fprintf(stderr, "Failed to create specified HW device.\n");
> +        return err;
> +    }
> +    ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);
> +
> +    return err;
> +}
> +
> +static int init_filters(AVFormatContext *fmt_ctx, AVCodecContext
*dec_ctx,
> +                        int video_stream_index, const char
*filters_descr)
> +{
> +    char args[512];
> +    int ret = 0;
> +    const AVFilter *buffersrc  = avfilter_get_by_name("buffer");
> +    const AVFilter *buffersink = avfilter_get_by_name("buffersink");
> +    AVFilterInOut *outputs = avfilter_inout_alloc();
> +    AVFilterInOut *inputs  = avfilter_inout_alloc();
> +    AVRational time_base =
fmt_ctx->streams[video_stream_index]->time_base;
> +    AVBufferSrcParameters *par = av_buffersrc_parameters_alloc();
> +
> +    filter_graph = avfilter_graph_alloc();
> +    if (!outputs || !inputs || !filter_graph || !par) {
> +        ret = AVERROR(ENOMEM);
> +        goto end;
> +    }
> +
> +    /* buffer video source: the decoded frames from the decoder will be
inserted here. */
> +    snprintf(args, sizeof(args),
> +
 "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
> +            dec_ctx->width, dec_ctx->height, AV_PIX_FMT_VAAPI,
> +            time_base.num, time_base.den,
> +            dec_ctx->sample_aspect_ratio.num,
dec_ctx->sample_aspect_ratio.den);
> +
> +    ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
> +                                       args, NULL, filter_graph);
> +    if (ret < 0) {
> +        fprintf(stderr, "Cannot create buffer source\n");
> +        goto end;
> +    }
> +    par->hw_frames_ctx = dec_ctx->hw_frames_ctx;
> +    ret = av_buffersrc_parameters_set(buffersrc_ctx, par);
> +    if (ret < 0)
> +        goto end;
> +    av_freep(&par);
> +
> +    /* buffer video sink: to terminate the filter chain. */
> +    ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink,
"out",
> +                                       NULL, NULL, filter_graph);
> +    if (ret < 0) {
> +        fprintf(stderr, "Cannot create buffer sink\n");
> +        goto end;
> +    }
> +
> +    /*
> +     * Set the endpoints for the filter graph. The filter_graph will
> +     * be linked to the graph described by filters_descr.
> +     */
> +
> +    /*
> +     * The buffer source output must be connected to the input pad of
> +     * the first filter described by filters_descr; since the first
> +     * filter input label is not specified, it is set to "in" by
> +     * default.
> +     */
> +    outputs->name       = av_strdup("in");
> +    outputs->filter_ctx = buffersrc_ctx;
> +    outputs->pad_idx    = 0;
> +    outputs->next       = NULL;
> +
> +    /*
> +     * The buffer sink input must be connected to the output pad of
> +     * the last filter described by filters_descr; since the last
> +     * filter output label is not specified, it is set to "out" by
> +     * default.
> +     */
> +    inputs->name       = av_strdup("out");
> +    inputs->filter_ctx = buffersink_ctx;
> +    inputs->pad_idx    = 0;
> +    inputs->next       = NULL;
> +
> +    if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr,
> +                                        &inputs, &outputs, NULL)) < 0)
> +        goto end;
> +
> +    for (int i = 0; i < filter_graph->nb_filters; i++) {
> +        filter_graph->filters[i]->hw_device_ctx =
av_buffer_ref(hw_device_ctx);
> +        if (!filter_graph->filters[i]->hw_device_ctx) {
> +            ret = AVERROR(ENOMEM);
> +            goto end;
> +        }
> +    }
> +
> +    if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
> +        goto end;
> +
> +end:
> +    avfilter_inout_free(&inputs);
> +    avfilter_inout_free(&outputs);
> +
> +    return ret;
> +}
> +
> +static enum AVPixelFormat get_hw_format(AVCodecContext *ctx,
> +                                        const enum AVPixelFormat
*pix_fmts)
> +{
> +    const enum AVPixelFormat *p;
> +
> +    for (p = pix_fmts; *p != -1; p++) {
> +        if (*p == hw_pix_fmt)
> +            return *p;
> +    }
> +
> +    fprintf(stderr, "Failed to get HW surface format.\n");
> +    return AV_PIX_FMT_NONE;
> +}
> +
> +static int decode_filte(AVFormatContext *input_ctx, AVCodecContext
*avctx,
> +                        int video_stream, AVPacket *packet)
> +{
> +    AVFrame *frame = NULL;
> +    AVFrame *filt_frame = NULL;
> +    uint8_t *buffer = NULL;
> +    int size;
> +    int ret = 0;
> +
> +    ret = avcodec_send_packet(avctx, packet);
> +    if (ret < 0) {
> +        fprintf(stderr, "Error during decoding\n");
> +        return ret;
> +    }
> +
> +    frame = av_frame_alloc();
> +    filt_frame = av_frame_alloc();
> +    if (!frame || !filt_frame) {
> +        fprintf(stderr, "Can not alloc frame\n");
> +        ret = AVERROR(ENOMEM);
> +        return ret;
> +    }
> +
> +    while (1) {
> +        ret = avcodec_receive_frame(avctx, frame);
> +        if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
> +            av_frame_free(&frame);
> +            av_frame_free(&filt_frame);
> +            return 0;
> +        } else if (ret < 0) {
> +            fprintf(stderr, "Error while decoding\n");
> +            goto fail;
> +        }
> +
> +        if (frame->format == hw_pix_fmt) {
> +            if (!init_filter) {
> +                if ((ret = init_filters(input_ctx, avctx,
> +                                        video_stream, filter_descr)) <
0) {
> +                    fprintf(stderr, "Failed to init filter\n");
> +                    goto fail;
> +                }
> +                init_filter = 1;
> +            }
> +
> +            /* push the decoded frame into the filtergraph */
> +            if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame,
AV_BUFFERSRC_FLAG_KEEP_REF) < 0) {
> +                av_log(NULL, AV_LOG_ERROR, "Error while feeding the
filtergraph\n");
> +                goto fail;
> +            }
> +
> +            /* pull filtered frames from the filtergraph */
> +            while (1) {
> +                ret = av_buffersink_get_frame(buffersink_ctx,
filt_frame);
> +                if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
> +                    break;
> +                if (ret < 0)
> +                    goto fail;
> +
> +                size = av_image_get_buffer_size(filt_frame->format,
filt_frame->width,
> +                                                filt_frame->height, 1);
> +                buffer = av_malloc(size);
> +                if (!buffer) {
> +                    fprintf(stderr, "Can not alloc buffer\n");
> +                    ret = AVERROR(ENOMEM);
> +                    goto fail;
> +                }
> +                ret = av_image_copy_to_buffer(buffer, size,
> +                                              (const uint8_t * const
*)filt_frame->data,
> +                                              (const int
*)filt_frame->linesize, filt_frame->format,
> +                                              filt_frame->width,
filt_frame->height, 1);
> +                if (ret < 0) {
> +                    fprintf(stderr, "Can not copy image to buffer\n");
> +                    goto fail;
> +                }
> +
> +                if ((ret = fwrite(buffer, 1, size, output_file)) < 0) {
> +                    fprintf(stderr, "Failed to dump filted raw data.\n");
> +                    goto fail;
> +                }
> +
> +                av_frame_unref(filt_frame);
> +                av_freep(&buffer);
> +            }
> +            av_frame_unref(frame);
> +        }
> +    }
> +
> +fail:
> +    av_frame_free(&frame);
> +    av_frame_free(&filt_frame);
> +    av_freep(&buffer);
> +
> +    return ret;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> +    AVFormatContext *input_ctx = NULL;
> +    int video_stream, ret;
> +    AVStream *video = NULL;
> +    AVCodecContext *decoder_ctx = NULL;
> +    AVCodec *decoder = NULL;
> +    AVPacket packet;
> +    enum AVHWDeviceType type;
> +    int i;
> +
> +    if (argc < 3) {
> +        fprintf(stderr, "Usage: %s <input file> <output file>\n",
argv[0]);
> +        return -1;
> +    }
> +
> +    type = av_hwdevice_find_type_by_name("vaapi");
> +    if (type == AV_HWDEVICE_TYPE_NONE) {
> +        fprintf(stderr, "Device type vaapi is not supported.\n");
> +        fprintf(stderr, "Available device types:");
> +        while((type = av_hwdevice_iterate_types(type)) !=
AV_HWDEVICE_TYPE_NONE)
> +            fprintf(stderr, " %s", av_hwdevice_get_type_name(type));
> +        fprintf(stderr, "\n");
> +        return -1;
> +    }
> +
> +    /* open the input file */
> +    if (avformat_open_input(&input_ctx, argv[1], NULL, NULL) != 0) {
> +        fprintf(stderr, "Cannot open input file '%s'\n", argv[2]);
> +        return -1;
> +    }
> +
> +    if (avformat_find_stream_info(input_ctx, NULL) < 0) {
> +        fprintf(stderr, "Cannot find input stream information.\n");
> +        return -1;
> +    }
> +
> +    /* find the video stream information */
> +    ret = av_find_best_stream(input_ctx, AVMEDIA_TYPE_VIDEO, -1, -1,
&decoder, 0);
> +    if (ret < 0) {
> +        fprintf(stderr, "Cannot find a video stream in the input
file\n");
> +        return -1;
> +    }
> +    video_stream = ret;
> +
> +    for (i = 0;; i++) {
> +        const AVCodecHWConfig *config = avcodec_get_hw_config(decoder,
i);
> +        if (!config) {
> +            fprintf(stderr, "Decoder %s does not support device type
%s.\n",
> +                    decoder->name, av_hwdevice_get_type_name(type));
> +            return -1;
> +        }
> +        if (config->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX &&
> +            config->device_type == type) {
> +            hw_pix_fmt = config->pix_fmt;
> +            break;
> +        }
> +    }
> +
> +    if (!(decoder_ctx = avcodec_alloc_context3(decoder)))
> +        return AVERROR(ENOMEM);
> +
> +    video = input_ctx->streams[video_stream];
> +    if (avcodec_parameters_to_context(decoder_ctx, video->codecpar) < 0)
> +        return -1;
> +
> +    decoder_ctx->get_format  = get_hw_format;
> +
> +    if (init_hw_decode(decoder_ctx, type) < 0)
> +        return -1;
> +
> +    if ((ret = avcodec_open2(decoder_ctx, decoder, NULL)) < 0) {
> +        fprintf(stderr, "Failed to open codec for stream #%u\n",
video_stream);
> +        return -1;
> +    }
> +
> +    /* open the file to dump scaled data */
> +    output_file = fopen(argv[2], "w+");
> +
> +    /* actual decoding/scaling and dump the raw data */
> +    while (ret >= 0) {
> +        if ((ret = av_read_frame(input_ctx, &packet)) < 0)
> +            break;
> +
> +        if (video_stream == packet.stream_index)
> +            ret = decode_filte(input_ctx, decoder_ctx, video_stream,
&packet);
> +
> +        av_packet_unref(&packet);
> +    }
> +
> +    /* flush the decoder/avfilter */
> +    packet.data = NULL;
> +    packet.size = 0;
> +    ret = decode_filte(input_ctx, decoder_ctx, video_stream, &packet);
> +    av_packet_unref(&packet);
> +
> +    if (output_file)
> +        fclose(output_file);
> +    avfilter_graph_free(&filter_graph);
> +    avcodec_free_context(&decoder_ctx);
> +    avformat_close_input(&input_ctx);
> +    av_buffer_unref(&hw_device_ctx);
> +
> +    return 0;
> +}
> --


Ping, this is the sample to demo how to enable the HWAccel decoder/scaling
from API level, any comments will be welcome. Thanks.


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