2 * Copyright (c) 2017 Jun Zhao
3 * Copyright (c) 2017 Kaixuan Liu
5 * HW Acceleration API (video decoding) decode sample
7 * This file is part of FFmpeg.
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 * HW-Accelerated decoding example.
28 * @example hw_decode.c
29 * This example shows how to do HW-accelerated decoding with output
30 * frames from the HW video surfaces.
35 #include <libavcodec/avcodec.h>
36 #include <libavformat/avformat.h>
37 #include <libavutil/pixdesc.h>
38 #include <libavutil/hwcontext.h>
39 #include <libavutil/opt.h>
40 #include <libavutil/avassert.h>
41 #include <libavutil/imgutils.h>
43 static AVBufferRef *hw_device_ctx = NULL;
44 static enum AVPixelFormat hw_pix_fmt;
45 static FILE *output_file = NULL;
47 static enum AVPixelFormat find_fmt_by_hw_type(const enum AVHWDeviceType type)
49 enum AVPixelFormat fmt;
52 case AV_HWDEVICE_TYPE_VAAPI:
53 fmt = AV_PIX_FMT_VAAPI;
55 case AV_HWDEVICE_TYPE_DXVA2:
56 fmt = AV_PIX_FMT_DXVA2_VLD;
58 case AV_HWDEVICE_TYPE_D3D11VA:
59 fmt = AV_PIX_FMT_D3D11;
61 case AV_HWDEVICE_TYPE_VDPAU:
62 fmt = AV_PIX_FMT_VDPAU;
64 case AV_HWDEVICE_TYPE_VIDEOTOOLBOX:
65 fmt = AV_PIX_FMT_VIDEOTOOLBOX;
68 fmt = AV_PIX_FMT_NONE;
75 static int hw_decoder_init(AVCodecContext *ctx, const enum AVHWDeviceType type)
79 if ((err = av_hwdevice_ctx_create(&hw_device_ctx, type,
80 NULL, NULL, 0)) < 0) {
81 fprintf(stderr, "Failed to create specified HW device.\n");
84 ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);
89 static enum AVPixelFormat get_hw_format(AVCodecContext *ctx,
90 const enum AVPixelFormat *pix_fmts)
92 const enum AVPixelFormat *p;
94 for (p = pix_fmts; *p != -1; p++) {
99 fprintf(stderr, "Failed to get HW surface format.\n");
100 return AV_PIX_FMT_NONE;
103 static int decode_write(AVCodecContext *avctx, AVPacket *packet)
105 AVFrame *frame = NULL, *sw_frame = NULL;
106 AVFrame *tmp_frame = NULL;
107 uint8_t *buffer = NULL;
111 ret = avcodec_send_packet(avctx, packet);
113 fprintf(stderr, "Error during decoding\n");
118 if (!(frame = av_frame_alloc()) || !(sw_frame = av_frame_alloc())) {
119 fprintf(stderr, "Can not alloc frame\n");
120 ret = AVERROR(ENOMEM);
124 ret = avcodec_receive_frame(avctx, frame);
125 if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
126 av_frame_free(&frame);
127 av_frame_free(&sw_frame);
129 } else if (ret < 0) {
130 fprintf(stderr, "Error while decoding\n");
134 if (frame->format == hw_pix_fmt) {
135 /* retrieve data from GPU to CPU */
136 if ((ret = av_hwframe_transfer_data(sw_frame, frame, 0)) < 0) {
137 fprintf(stderr, "Error transferring the data to system memory\n");
140 tmp_frame = sw_frame;
144 size = av_image_get_buffer_size(tmp_frame->format, tmp_frame->width,
145 tmp_frame->height, 1);
146 buffer = av_malloc(size);
148 fprintf(stderr, "Can not alloc buffer\n");
149 ret = AVERROR(ENOMEM);
152 ret = av_image_copy_to_buffer(buffer, size,
153 (const uint8_t * const *)tmp_frame->data,
154 (const int *)tmp_frame->linesize, tmp_frame->format,
155 tmp_frame->width, tmp_frame->height, 1);
157 fprintf(stderr, "Can not copy image to buffer\n");
161 if ((ret = fwrite(buffer, 1, size, output_file)) < 0) {
162 fprintf(stderr, "Failed to dump raw data.\n");
167 av_frame_free(&frame);
168 av_frame_free(&sw_frame);
178 int main(int argc, char *argv[])
180 AVFormatContext *input_ctx = NULL;
181 int video_stream, ret;
182 AVStream *video = NULL;
183 AVCodecContext *decoder_ctx = NULL;
184 AVCodec *decoder = NULL;
186 enum AVHWDeviceType type;
189 fprintf(stderr, "Usage: %s <vaapi|vdpau|dxva2|d3d11va> <input file> <output file>\n", argv[0]);
195 type = av_hwdevice_find_type_by_name(argv[1]);
196 hw_pix_fmt = find_fmt_by_hw_type(type);
197 if (hw_pix_fmt == -1) {
198 fprintf(stderr, "Cannot support '%s' in this example.\n", argv[1]);
202 /* open the input file */
203 if (avformat_open_input(&input_ctx, argv[2], NULL, NULL) != 0) {
204 fprintf(stderr, "Cannot open input file '%s'\n", argv[2]);
208 if (avformat_find_stream_info(input_ctx, NULL) < 0) {
209 fprintf(stderr, "Cannot find input stream information.\n");
213 /* find the video stream information */
214 ret = av_find_best_stream(input_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &decoder, 0);
216 fprintf(stderr, "Cannot find a video stream in the input file\n");
221 if (!(decoder_ctx = avcodec_alloc_context3(decoder)))
222 return AVERROR(ENOMEM);
224 video = input_ctx->streams[video_stream];
225 if (avcodec_parameters_to_context(decoder_ctx, video->codecpar) < 0)
228 decoder_ctx->get_format = get_hw_format;
229 av_opt_set_int(decoder_ctx, "refcounted_frames", 1, 0);
231 if (hw_decoder_init(decoder_ctx, type) < 0)
234 if ((ret = avcodec_open2(decoder_ctx, decoder, NULL)) < 0) {
235 fprintf(stderr, "Failed to open codec for stream #%u\n", video_stream);
239 /* open the file to dump raw data */
240 output_file = fopen(argv[3], "w+");
242 /* actual decoding and dump the raw data */
244 if ((ret = av_read_frame(input_ctx, &packet)) < 0)
247 if (video_stream == packet.stream_index)
248 ret = decode_write(decoder_ctx, &packet);
250 av_packet_unref(&packet);
253 /* flush the decoder */
256 ret = decode_write(decoder_ctx, &packet);
257 av_packet_unref(&packet);
261 avcodec_free_context(&decoder_ctx);
262 avformat_close_input(&input_ctx);
263 av_buffer_unref(&hw_device_ctx);