On 2017/3/21 12:57, wm4 wrote:
> On Tue, 21 Mar 2017 12:45:26 +0800
> Jun Zhao <mypopy...@gmail.com> wrote:
>
>> From 6b56c541ed7dd271ad0aa6eb6412a8427f009525 Mon Sep 17 00:00:00 2001
>> From: Jun Zhao <jun.z...@intel.com>
>> Date: Tue, 21 Mar 2017 11:04:41 +0800
>> Subject: [PATCH] examples/vaapi_dec: Add a VA-API hwaccel decoding example.
>>
>> Add a VA-API hwaccel decoding example.
>>
>> Signed-off-by: Liu, Kaixuan <kaixuan....@intel.com>
>> Signed-off-by: Jun Zhao <jun.z...@intel.com>
>> ---
>> doc/examples/vaapi_dec.c | 346
>> +++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 346 insertions(+)
>> create mode 100644 doc/examples/vaapi_dec.c
>>
>> diff --git a/doc/examples/vaapi_dec.c b/doc/examples/vaapi_dec.c
>> new file mode 100644
>> index 0000000..f975d86
>> --- /dev/null
>> +++ b/doc/examples/vaapi_dec.c
>> @@ -0,0 +1,346 @@
>> +/*
>> + * Video Acceleration API (video decoding) decode 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 decoding example.
>> + *
>> + * @example vaapi_dec.c
>> + * This example shows how to do VAAPI-accelerated decoding with output
>> + * frames from the VAAPI video surfaces.
>> + */
>> +
>> +#include <stdio.h>
>> +#include <libavcodec/avcodec.h>
>> +#include <libavcodec/vaapi.h>
>> +#include <libavformat/avformat.h>
>> +#include <libswscale/swscale.h>
>> +#include <libavutil/pixdesc.h>
>> +#include <libavutil/hwcontext.h>
>> +#include <libavutil/opt.h>
>> +#include <libavutil/hwcontext_vaapi.h>
>> +#include <libavutil/avassert.h>
>> +#include <va/va.h>
>> +#include <va/va_x11.h>
>> +#include <va/va_drm.h>
>> +
>> +#define DEFAULT_SURFACES 20
>> +static enum AVPixelFormat decode_format = AV_PIX_FMT_NV12;
>> +static enum AVPixelFormat output_format = AV_PIX_FMT_NV12; /* default
>> output format nv12 */
>> +static AVBufferRef *frames_ref = NULL;
>> +static AVBufferRef *device_ref = NULL;
>> +FILE *output_file = NULL;
>> +
>> +void decoder_uninit_vaapi(AVCodecContext *avctx, AVVAAPIDeviceContext
>> *hwctx)
>> +{
>> + if (hwctx) {
>> + av_buffer_unref(&frames_ref);
>> + av_buffer_unref(&device_ref);
>> + }
>> + return;
>> +}
>> +
>> +int decoder_init_vaapi(AVCodecContext *ctx)
>> +{
>> + AVBufferRef *hw_device_ctx = NULL;
>> + AVHWFramesContext *frames;
>> + int err = 0;
>> + char *dev_name = "/dev/dri/renderD128";
>> + AVBufferRef *device_ref = NULL;
>> + AVHWDeviceContext *device = NULL;
>> + AVVAAPIDeviceContext *hwctx = NULL;
>> +
>> + if ((err = av_hwdevice_ctx_create(&hw_device_ctx,
>> AV_HWDEVICE_TYPE_VAAPI,
>> + dev_name, NULL, 0)) < 0) {
>> + fprintf(stderr, "Failed to create a VAAPI device.\n");
>> + return err;
>> + }
>> +
>> + device_ref = av_buffer_ref(hw_device_ctx);
>> + device = (AVHWDeviceContext *)device_ref->data;
>> + hwctx = (AVVAAPIDeviceContext *)device->hwctx;
>> +
>> + ctx->pix_fmt = output_format;
>> + if (!(frames_ref = av_hwframe_ctx_alloc(device_ref))) {
>> + fprintf(stderr, "Failed to create VAAPI frame context.\n");
>> + err = AVERROR(ENOMEM);
>> + goto fail;
>> + }
>> + frames = (AVHWFramesContext *)frames_ref->data;
>> + frames->format = AV_PIX_FMT_VAAPI;
>> + frames->sw_format = decode_format;
>> + frames->width = ctx->coded_width;
>> + frames->height = ctx->coded_height;
>> + frames->initial_pool_size = DEFAULT_SURFACES;
>> + if ((err = av_hwframe_ctx_init(frames_ref)) < 0) {
>> + fprintf(stderr, "Failed to initialize VAAPI frame.\n");
>> + goto fail;
>> + }
>> +
>> + ctx->hw_frames_ctx = av_buffer_ref(frames_ref);
>> + if (!ctx->hw_frames_ctx) {
>> + err = AVERROR(ENOMEM);
>> + fprintf(stderr, "Failed to ref VAAPI frame.\n");
>> + goto fail;
>> + }
>
> All of this code (except device creation) will be unnecessary once the
> Libav change of improving the hw decoding API has been merged. See e.g.:
>
> https://git.libav.org/?p=libav.git;a=commit;h=62a1ef9f26c654a3e988aa465c4ac1d776c4c356
>
I like this change, hope it can be move to FFmpeg as quick. Then I will rework
this part.
>> +
>> +fail:
>> + if (err < 0)
>> + decoder_uninit_vaapi(ctx, hwctx);
>> + return err;
>> +}
>> +
>> +static enum AVPixelFormat get_hw_vaapi_format(AVCodecContext *ctx,
>> + const enum AVPixelFormat
>> *pix_fmts)
>> +{
>> + const enum AVPixelFormat *p;
>> + int ret;
>> +
>> + for (p = pix_fmts; *p != -1; p++) {
>> + const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(*p);
>> + if (!(desc->flags & AV_PIX_FMT_FLAG_HWACCEL))
>> + break;
>> +
>> + if (!(strstr(desc->name, "vaapi")))
>> + continue;
>> +
>> + if ((ret = decoder_init_vaapi(ctx)) < 0) {
>> + fprintf(stderr, "hwaccel for decoder(VAAPI) cannot be
>> initialized.\n");
>> + return AV_PIX_FMT_NONE;
>> + }
>> + break;
>> + }
>> + return *p;
>> +}
>> +
>> +static int get_hw_vaapi_buffer(AVCodecContext *ctx, AVFrame *frame, int
>> flags)
>> +{
>> + int err;
>> + if ((err = av_hwframe_get_buffer(frames_ref, frame, 0)) < 0)
>> + av_log(NULL, AV_LOG_ERROR, "Failed to allocate decoder surface.\n");
>> +
>> + return err;
>> +}
>
> This function will also be unnecessary.
>
>> +
>> +int retrieve_data(AVFrame *input)
>> +{
>> + AVFrame *output = 0;
>> + int err;
>> + av_assert0(input->format == AV_PIX_FMT_VAAPI);
>> +
>> + if (output_format == AV_PIX_FMT_VAAPI)
>> + return 0;
>
> Not necessary to check the pixfmt. As long as the AVFrame has a
> hw_frames_ctx set, it should work. (Even if not, the transfer data
> function would just return AVERROR(ENOSYS).)
Agree
>
>> +
>> + if (!(output = av_frame_alloc()))
>> + return AVERROR(ENOMEM);
>> + output->format = output_format;
>> + if ((err = av_hwframe_transfer_data(output, input, 0)) < 0) {
>> + fprintf(stderr, "Failed to transfer data to output frame: %d.\n",
>> err);
>> + goto fail;
>> + }
>> +
>> + if ((err = av_frame_copy_props(output, input)) < 0) {
>> + av_frame_unref(output);
>> + goto fail;
>> + }
>> +
>> + av_frame_unref(input);
>> + av_frame_move_ref(input, output);
>> + av_frame_free(&output);
>> + return 0;
>> +
>> +fail:
>> + av_frame_free(&output);
>> + return err;
>> +}
>> +
>> +int write_frame(AVFrame *frame)
>> +{
>> + int idx, size;
>> + int width = frame->width;
>> + int height = frame->height;
>> +
>> + av_assert0(frame && frame->data[0] && output_file);
>> +
>> + for (idx = 0; idx < height; idx++) {
>> + if ((size = fwrite(frame->data[0] + idx*frame->linesize[0],
>> + 1, width, output_file)) < 0) {
>> + fprintf(stderr, "Dump Y to file error.\n");
>> + return -1;
>> + }
>> + }
>> +
>> + height >>= 1;
>> + for (idx = 0; idx < height; idx++) {
>> + if ((size = fwrite(frame->data[1] + idx*frame->linesize[1],
>> + 1, width, output_file)) < 0) {
>> + fprintf(stderr, "Dump UV to file error.\n");
>> + return -1;
>> + }
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +int decode_write(AVCodecContext *avctx, AVPacket packet, int flush)
>> +{
>> + AVFrame *frame = NULL;
>> + int ret = 0, got_frame = 0;
>> +
>> + if (!(frame = av_frame_alloc()))
>> + return AVERROR(ENOMEM);
>> +
>> + if ((ret = avcodec_decode_video2(avctx, frame, &got_frame, &packet)) <
>> 0) {
>> + fprintf(stderr, "Error during decoding\n");
>> + goto fail;
>> + }
>
> Deprecated API use.
Will rework with send/receive decoding API.
>
>> +
>> + if (got_frame) {
>> + if (AV_PIX_FMT_VAAPI == frame->format) {
>
> I think we want to avoid "yoda conditions" in this project.
>
>> + /* retrieve data from GPU to CPU */
>> + if ((ret = retrieve_data(frame)) < 0)
>> + goto fail;
>> +
>> + if ((ret = write_frame(frame)) < 0)
>> + goto fail;
>> + }
>> + } else if (flush == 1) {
>> + ret = -1;
>> + }
>> +
>> +fail:
>> + av_frame_free(&frame);
>> + return ret;
>> +}
>> +
>> +/* flush the decoder */
>> +int flush(AVCodecContext *avctx)
>> +{
>> + AVPacket packet;
>> + int ret = 0;
>> +
>> + av_init_packet(&packet);
>> + packet.data = NULL;
>> + packet.size = 0;
>> +
>> + while (1) {
>> + if ((ret = decode_write(avctx, packet, 1)) < 0)
>> + break;
>> + }
>> + av_packet_unref(&packet);
>> +
>> + return 0;
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + AVFormatContext *input_ctx = NULL;
>> + int i,video_stream,ret;
>> + AVCodecContext *decoder_ctx = NULL;
>> + AVCodec *decoder = NULL;
>> + AVPacket packet;
>> +
>> + if (argc < 3) {
>> + fprintf(stderr, "Usage: %s <input file> <output file>\n", argv[0]);
>> + return -1;
>> + }
>> +
>> + av_register_all();
>> +
>> + /* open the input file */
>> + if (avformat_open_input(&input_ctx, argv[1], NULL, NULL) != 0) {
>> + fprintf(stderr, "Cannot open input file '%s'\n", argv[1]);
>> + return -1;
>> + }
>> +
>> + if (avformat_find_stream_info(input_ctx, NULL) < 0) {
>> + fprintf(stderr, "Couldn't find input stream information.\n");
>> + return -1;
>> + }
>> +
>> + /* find the video stream information */
>> + video_stream = -1;
>> + for (i = 0; i < input_ctx->nb_streams; i++) {
>> + AVStream *st = input_ctx->streams[i];
>> + if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
>> + /* NOTE: just handle the first video stream */
>> + video_stream = i;
>> + break;
>> + }
>> + }
>> +
>> + if (video_stream == -1) {
>> + fprintf(stderr, "No find a video stream in the input file.\n");
>> + return -1;
>> + }
>> +
>> + /* initialize the video decoder */
>> + if (!(decoder =
>> avcodec_find_decoder(input_ctx->streams[video_stream]->codecpar->codec_id)))
>> {
>> + fprintf(stderr, "Could not find input codec\n");
>> + avformat_close_input(&input_ctx);
>> + return -1;
>> + }
>> +
>> + if (!(decoder_ctx = avcodec_alloc_context3(decoder)))
>> + return AVERROR(ENOMEM);
>> +
>> + if (avcodec_parameters_to_context(decoder_ctx,
>> +
>> input_ctx->streams[video_stream]->codecpar) < 0) {
>> + avcodec_free_context(&decoder_ctx);
>> + avformat_close_input(&input_ctx);
>> + return -1;
>> + }
>> +
>> + decoder_ctx->get_format = get_hw_vaapi_format;
>> + decoder_ctx->get_buffer2 = get_hw_vaapi_buffer;
>> + av_opt_set_int(decoder_ctx, "refcounted_frames", 1, 0);
>> +
>> + if ((ret = avcodec_open2(decoder_ctx, decoder, NULL)) < 0) {
>> + fprintf(stderr, "Failed to open codec for stream #%u\n", i);
>> + return ret;
>> + }
>> +
>> + /* open the output file to dump YUV */
>> + output_file = fopen(argv[2], "w+");
>> +
>> + /* actual decoding and dump the YUV data */
>> + while (av_read_frame(input_ctx, &packet) >= 0) {
>> + if (video_stream == packet.stream_index)
>> + ret = decode_write(decoder_ctx, packet, 0);
>> + av_packet_unref(&packet);
>> +
>> + if (ret < 0)
>> + break;
>> + }
>> +
>> + /* flush the decoder */
>> + flush(decoder_ctx);
>> +
>> + if (output_file)
>> + fclose(output_file);
>> + avcodec_free_context(&decoder_ctx);
>> + avformat_close_input(&input_ctx);
>> +
>> + av_buffer_unref(&frames_ref);
>> + av_buffer_unref(&device_ref);
>> +
>> + return ret;
>> +}
>> +
>
> Rest seems ok.
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel@ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
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