On 2017/7/21 6:44, Mark Thompson wrote:
> On 20/07/17 08:54, Jun Zhao wrote:
>> V4: fix potential memory leak issue base on Steven Liu's review.
>> V3: re-work to support the other hwaccels, rename from vaapi_dec.c to
>> hw_decode.c.
>> just test with vaapi, dxva2|d3d11va|videotoolbox might work as well.
>> V2: re-work with new hw decoding API.
>>
>> From 718f92731d308423e5a09d0384f7bf2361f5a307 Mon Sep 17 00:00:00 2001
>> From: Jun Zhao <jun.z...@intel.com>
>> Date: Thu, 20 Jul 2017 00:58:56 -0400
>> Subject: [PATCH V4] examples/hw_decode: Add a HWAccel decoding example.
>>
>> Add a HWAccel decoding example.
>>
>> Just test with vaapi, dxva2|d3d11va|videotoolbox might work as well.
>>
>> Signed-off-by: Liu, Kaixuan <kaixuan....@intel.com>
>> Signed-off-by: Jun Zhao <jun.z...@intel.com>
>> ---
>> doc/examples/hw_decode.c | 249
>> +++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 249 insertions(+)
>> create mode 100644 doc/examples/hw_decode.c
>>
>> diff --git a/doc/examples/hw_decode.c b/doc/examples/hw_decode.c
>> new file mode 100644
>> index 0000000000..0e77ee877f
>> --- /dev/null
>> +++ b/doc/examples/hw_decode.c
>> @@ -0,0 +1,249 @@
>> +/*
>> + * Copyright (c) 2017 Jun Zhao
>> + * Copyright (c) 2017 Kaixuan Liu
>> + *
>> + * HW 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
>> + * HW-Accelerated decoding example.
>> + *
>> + * @example hw_decode.c
>> + * This example shows how to do HW-accelerated decoding with output
>> + * frames from the HW video surfaces.
>> + */
>> +
>> +#include <stdio.h>
>> +
>> +#include <libavcodec/avcodec.h>
>> +#include <libavformat/avformat.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;
>> +FILE *output_file = NULL;
>> +
>> +static enum AVPixelFormat hw_pix_fmts[] = {
>> + [AV_HWDEVICE_TYPE_CUDA] = AV_PIX_FMT_CUDA,
>> + [AV_HWDEVICE_TYPE_DXVA2] = AV_PIX_FMT_DXVA2_VLD,
>> + [AV_HWDEVICE_TYPE_D3D11VA] = AV_PIX_FMT_D3D11VA_VLD,
>
> AV_PIX_FMT_D3D11 (this was changed recently).
>
>> + [AV_HWDEVICE_TYPE_QSV] = AV_PIX_FMT_QSV,
>> + [AV_HWDEVICE_TYPE_VAAPI] = AV_PIX_FMT_VAAPI,
>> + [AV_HWDEVICE_TYPE_VDPAU] = AV_PIX_FMT_VDPAU,
>> + [AV_HWDEVICE_TYPE_VIDEOTOOLBOX] = AV_PIX_FMT_VIDEOTOOLBOX,
>> +};
>
> Neither CUDA nor QSV will work here, as they are dummy hwaccels used on other
> decoders. Just leave the five real hwaccels.
>
>> +
>> +static enum AVPixelFormat find_fmt_by_hw_type(const enum AVHWDeviceType
>> type)
>> +{
>> + if (type >= 0 && type < FF_ARRAY_ELEMS(hw_pix_fmts))
>> + return hw_pix_fmts[type];
>> + else
>> + return AV_PIX_FMT_NONE;
>> +}
>> +
>> +static int hw_decoder_init(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 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_write(AVCodecContext *avctx, AVPacket *packet)
>> +{
>> + AVFrame *frame = NULL, *sw_frame = NULL;
>> + AVFrame *tmp_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;
>> + }
>> +
>> + while (ret >= 0) {
>> + if (!(frame = av_frame_alloc()) || !(sw_frame = av_frame_alloc())) {
>> + fprintf(stderr, "Can not alloc frame\n");
>> + ret = AVERROR(ENOMEM);
>> + goto fail;
>> + }
>> +
>> + ret = avcodec_receive_frame(avctx, frame);
>> + if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
>> + break;
>> + else if (ret < 0) {
>> + fprintf(stderr, "Error while decoding\n");
>> + goto fail;
>> + }
>> +
>> + if (frame->format == hw_pix_fmt) {
>> + /* retrieve data from GPU to CPU */
>> + if ((ret = av_hwframe_transfer_data(sw_frame, frame, 0)) < 0) {
>> + fprintf(stderr, "Error transferring the data to system
>> memory\n");
>> + goto fail;
>> + }
>> + tmp_frame = sw_frame;
>> + } else
>> + tmp_frame = frame;
>> +
>> + size = av_image_get_buffer_size(tmp_frame->format, tmp_frame->width,
>> + tmp_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
>> *)tmp_frame->data,
>> + (const int *)tmp_frame->linesize,
>> tmp_frame->format,
>> + tmp_frame->width, tmp_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 raw data.\n");
>> + goto fail;
>> + }
>> +
>> + fail:
>> + av_frame_free(&frame);
>> + av_frame_free(&sw_frame);
>> + if (buffer)
>> + av_freep(&buffer);
>> + if (ret < 0)
>> + return ret;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + AVFormatContext *input_ctx = NULL;
>> + int video_stream, ret;
>> + AVCodecContext *decoder_ctx = NULL;
>> + AVCodec *decoder = NULL;
>> + AVPacket packet;
>> + enum AVHWDeviceType type;
>> +
>> + if (argc < 4) {
>> + fprintf(stderr, "Usage: %s <vaapi|dxva2|d3d11va> <input file>
>> <output file>\n", argv[0]);
>> + return -1;
>> + }
>> +
>> + av_register_all();
>> +
>> + type = av_hwdevice_find_type_by_name(argv[1]);
>> + hw_pix_fmt = find_fmt_by_hw_type(type);
>> +
>> + /* open the input file */
>> + if (avformat_open_input(&input_ctx, argv[2], 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, "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;
>> +
>> + if (!(decoder_ctx = avcodec_alloc_context3(decoder)))
>> + return AVERROR(ENOMEM);
>> +
>> + AVStream *video = input_ctx->streams[video_stream];
>
> Mixed declarations and code.
Will split declarations and code
>
>> + if (avcodec_parameters_to_context(decoder_ctx, video->codecpar) < 0)
>> + return -1;
>> +
>> + decoder_ctx->get_format = get_hw_format;
>> + av_opt_set_int(decoder_ctx, "refcounted_frames", 1, 0);
>> +
>> + if (hw_decoder_init(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 raw data */
>> + output_file = fopen(argv[3], "w+");
>> +
>> + /* actual decoding 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_write(decoder_ctx, &packet);
>> +
>> + av_packet_unref(&packet);
>> + }
>> +
>> + /* flush the decoder */
>> + packet.data = NULL;
>> + packet.size = 0;
>> + ret = decode_write(decoder_ctx, &packet);
>> + av_packet_unref(&packet);
>> +
>> + if (output_file)
>> + fclose(output_file);
>> + avcodec_free_context(&decoder_ctx);
>> + avformat_close_input(&input_ctx);
>> + av_buffer_unref(&hw_device_ctx);
>> +
>> + return 0;
>> +}
>> --
>> 2.11.0
>>
>
> I tested DXVA2 and D3D11 (with the pixfmt changed) and they both work as
> expected.
>
> This should be in the build system so it's actually built by "make examples"
> (in configure and the Makefiles under doc - just copy one of the other codec
> examples).
>
> Can anyone else test videotoolbox?
>
> Even without that, I'd be happy to apply this with the above fixed.
>
> Thanks,
Thanks for you test dxva2|d3d11, will submit V5 patch to follow the comments.
>
> - Mark
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>
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