FFmpeg 4.2.2
hw_decode.c
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1/*
2 * Copyright (c) 2017 Jun Zhao
3 * Copyright (c) 2017 Kaixuan Liu
4 *
5 * HW Acceleration API (video decoding) decode sample
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25
26/**
27 * @file
28 * HW-Accelerated decoding example.
29 *
30 * @example hw_decode.c
31 * This example shows how to do HW-accelerated decoding with output
32 * frames from the HW video surfaces.
33 */
34
35#include <stdio.h>
36
37#include <libavcodec/avcodec.h>
39#include <libavutil/pixdesc.h>
40#include <libavutil/hwcontext.h>
41#include <libavutil/opt.h>
42#include <libavutil/avassert.h>
43#include <libavutil/imgutils.h>
44
47static FILE *output_file = NULL;
48
49static int hw_decoder_init(AVCodecContext *ctx, const enum AVHWDeviceType type)
50{
51 int err = 0;
52
53 if ((err = av_hwdevice_ctx_create(&hw_device_ctx, type,
54 NULL, NULL, 0)) < 0) {
55 fprintf(stderr, "Failed to create specified HW device.\n");
56 return err;
57 }
59
60 return err;
61}
62
64 const enum AVPixelFormat *pix_fmts)
65{
66 const enum AVPixelFormat *p;
67
68 for (p = pix_fmts; *p != -1; p++) {
69 if (*p == hw_pix_fmt)
70 return *p;
71 }
72
73 fprintf(stderr, "Failed to get HW surface format.\n");
74 return AV_PIX_FMT_NONE;
75}
76
77static int decode_write(AVCodecContext *avctx, AVPacket *packet)
78{
79 AVFrame *frame = NULL, *sw_frame = NULL;
80 AVFrame *tmp_frame = NULL;
81 uint8_t *buffer = NULL;
82 int size;
83 int ret = 0;
84
85 ret = avcodec_send_packet(avctx, packet);
86 if (ret < 0) {
87 fprintf(stderr, "Error during decoding\n");
88 return ret;
89 }
90
91 while (1) {
92 if (!(frame = av_frame_alloc()) || !(sw_frame = av_frame_alloc())) {
93 fprintf(stderr, "Can not alloc frame\n");
94 ret = AVERROR(ENOMEM);
95 goto fail;
96 }
97
98 ret = avcodec_receive_frame(avctx, frame);
99 if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
101 av_frame_free(&sw_frame);
102 return 0;
103 } else if (ret < 0) {
104 fprintf(stderr, "Error while decoding\n");
105 goto fail;
106 }
107
108 if (frame->format == hw_pix_fmt) {
109 /* retrieve data from GPU to CPU */
110 if ((ret = av_hwframe_transfer_data(sw_frame, frame, 0)) < 0) {
111 fprintf(stderr, "Error transferring the data to system memory\n");
112 goto fail;
113 }
114 tmp_frame = sw_frame;
115 } else
116 tmp_frame = frame;
117
118 size = av_image_get_buffer_size(tmp_frame->format, tmp_frame->width,
119 tmp_frame->height, 1);
120 buffer = av_malloc(size);
121 if (!buffer) {
122 fprintf(stderr, "Can not alloc buffer\n");
123 ret = AVERROR(ENOMEM);
124 goto fail;
125 }
126 ret = av_image_copy_to_buffer(buffer, size,
127 (const uint8_t * const *)tmp_frame->data,
128 (const int *)tmp_frame->linesize, tmp_frame->format,
129 tmp_frame->width, tmp_frame->height, 1);
130 if (ret < 0) {
131 fprintf(stderr, "Can not copy image to buffer\n");
132 goto fail;
133 }
134
135 if ((ret = fwrite(buffer, 1, size, output_file)) < 0) {
136 fprintf(stderr, "Failed to dump raw data.\n");
137 goto fail;
138 }
139
140 fail:
142 av_frame_free(&sw_frame);
143 av_freep(&buffer);
144 if (ret < 0)
145 return ret;
146 }
147}
148
149int main(int argc, char *argv[])
150{
151 AVFormatContext *input_ctx = NULL;
152 int video_stream, ret;
153 AVStream *video = NULL;
155 AVCodec *decoder = NULL;
156 AVPacket packet;
157 enum AVHWDeviceType type;
158 int i;
159
160 if (argc < 4) {
161 fprintf(stderr, "Usage: %s <device type> <input file> <output file>\n", argv[0]);
162 return -1;
163 }
164
165 type = av_hwdevice_find_type_by_name(argv[1]);
166 if (type == AV_HWDEVICE_TYPE_NONE) {
167 fprintf(stderr, "Device type %s is not supported.\n", argv[1]);
168 fprintf(stderr, "Available device types:");
169 while((type = av_hwdevice_iterate_types(type)) != AV_HWDEVICE_TYPE_NONE)
170 fprintf(stderr, " %s", av_hwdevice_get_type_name(type));
171 fprintf(stderr, "\n");
172 return -1;
173 }
174
175 /* open the input file */
176 if (avformat_open_input(&input_ctx, argv[2], NULL, NULL) != 0) {
177 fprintf(stderr, "Cannot open input file '%s'\n", argv[2]);
178 return -1;
179 }
180
181 if (avformat_find_stream_info(input_ctx, NULL) < 0) {
182 fprintf(stderr, "Cannot find input stream information.\n");
183 return -1;
184 }
185
186 /* find the video stream information */
187 ret = av_find_best_stream(input_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &decoder, 0);
188 if (ret < 0) {
189 fprintf(stderr, "Cannot find a video stream in the input file\n");
190 return -1;
191 }
192 video_stream = ret;
193
194 for (i = 0;; i++) {
195 const AVCodecHWConfig *config = avcodec_get_hw_config(decoder, i);
196 if (!config) {
197 fprintf(stderr, "Decoder %s does not support device type %s.\n",
198 decoder->name, av_hwdevice_get_type_name(type));
199 return -1;
200 }
202 config->device_type == type) {
203 hw_pix_fmt = config->pix_fmt;
204 break;
205 }
206 }
207
208 if (!(decoder_ctx = avcodec_alloc_context3(decoder)))
209 return AVERROR(ENOMEM);
210
211 video = input_ctx->streams[video_stream];
213 return -1;
214
216
217 if (hw_decoder_init(decoder_ctx, type) < 0)
218 return -1;
219
220 if ((ret = avcodec_open2(decoder_ctx, decoder, NULL)) < 0) {
221 fprintf(stderr, "Failed to open codec for stream #%u\n", video_stream);
222 return -1;
223 }
224
225 /* open the file to dump raw data */
226 output_file = fopen(argv[3], "w+");
227
228 /* actual decoding and dump the raw data */
229 while (ret >= 0) {
230 if ((ret = av_read_frame(input_ctx, &packet)) < 0)
231 break;
232
233 if (video_stream == packet.stream_index)
234 ret = decode_write(decoder_ctx, &packet);
235
236 av_packet_unref(&packet);
237 }
238
239 /* flush the decoder */
240 packet.data = NULL;
241 packet.size = 0;
242 ret = decode_write(decoder_ctx, &packet);
243 av_packet_unref(&packet);
244
245 if (output_file)
246 fclose(output_file);
248 avformat_close_input(&input_ctx);
250
251 return 0;
252}
simple assert() macros that are a bit more flexible than ISO C assert().
Libavcodec external API header.
Main libavformat public API header.
static AVStream * video_stream
static AVFrame * frame
int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options)
Initialize the AVCodecContext to use the given AVCodec.
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
const AVCodecHWConfig * avcodec_get_hw_config(const AVCodec *codec, int index)
Retrieve supported hardware configurations for a codec.
int avcodec_parameters_to_context(AVCodecContext *codec, const AVCodecParameters *par)
Fill the codec context based on the values from the supplied codec parameters.
void avcodec_free_context(AVCodecContext **avctx)
Free the codec context and everything associated with it and write NULL to the provided pointer.
@ AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX
The codec supports this format via the hw_device_ctx interface.
Definition: avcodec.h:3427
int avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame)
Return decoded output data from a decoder.
int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)
Supply raw packet data as input to a decoder.
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, AVCodec **decoder_ret, int flags)
Find the "best" stream in the file.
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
int avformat_open_input(AVFormatContext **ps, const char *url, ff_const59 AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
void av_buffer_unref(AVBufferRef **buf)
Free a given reference and automatically free the buffer if there are no more references to it.
AVBufferRef * av_buffer_ref(AVBufferRef *buf)
Create a new reference to an AVBuffer.
#define AVERROR_EOF
End of file.
Definition: error.h:55
#define AVERROR(e)
Definition: error.h:43
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
void av_freep(void *ptr)
Free a memory block which has been allocated with a function of av_malloc() or av_realloc() family,...
void * av_malloc(size_t size) av_malloc_attrib
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
int av_image_get_buffer_size(enum AVPixelFormat pix_fmt, int width, int height, int align)
Return the size in bytes of the amount of data required to store an image with the given parameters.
int av_image_copy_to_buffer(uint8_t *dst, int dst_size, const uint8_t *const src_data[4], const int src_linesize[4], enum AVPixelFormat pix_fmt, int width, int height, int align)
Copy image data from an image into a buffer.
static int hw_decoder_init(AVCodecContext *ctx, const enum AVHWDeviceType type)
Definition: hw_decode.c:49
static AVBufferRef * hw_device_ctx
Definition: hw_decode.c:45
int main(int argc, char *argv[])
Definition: hw_decode.c:149
static FILE * output_file
Definition: hw_decode.c:47
static enum AVPixelFormat hw_pix_fmt
Definition: hw_decode.c:46
static int decode_write(AVCodecContext *avctx, AVPacket *packet)
Definition: hw_decode.c:77
static enum AVPixelFormat get_hw_format(AVCodecContext *ctx, const enum AVPixelFormat *pix_fmts)
Definition: hw_decode.c:63
enum AVHWDeviceType av_hwdevice_iterate_types(enum AVHWDeviceType prev)
Iterate over supported device types.
const char * av_hwdevice_get_type_name(enum AVHWDeviceType type)
Get the string name of an AVHWDeviceType.
enum AVHWDeviceType av_hwdevice_find_type_by_name(const char *name)
Look up an AVHWDeviceType by name.
int av_hwframe_transfer_data(AVFrame *dst, const AVFrame *src, int flags)
Copy data to or from a hw surface.
int av_hwdevice_ctx_create(AVBufferRef **device_ctx, enum AVHWDeviceType type, const char *device, AVDictionary *opts, int flags)
Open a device of the specified type and create an AVHWDeviceContext for it.
AVHWDeviceType
Definition: hwcontext.h:27
@ AV_HWDEVICE_TYPE_NONE
Definition: hwcontext.h:28
misc image utilities
AVOptions.
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
A reference to a data buffer.
Definition: buffer.h:81
main external API structure.
Definition: avcodec.h:1565
enum AVPixelFormat(* get_format)(struct AVCodecContext *s, const enum AVPixelFormat *fmt)
callback to negotiate the pixelFormat
Definition: avcodec.h:1817
AVBufferRef * hw_device_ctx
A reference to the AVHWDeviceContext describing the device which will be used by a hardware encoder/d...
Definition: avcodec.h:3314
enum AVHWDeviceType device_type
The device type associated with the configuration.
Definition: avcodec.h:3471
int methods
Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible setup methods which can be used...
Definition: avcodec.h:3464
enum AVPixelFormat pix_fmt
A hardware pixel format which the codec can use.
Definition: avcodec.h:3459
AVCodec.
Definition: avcodec.h:3481
const char * name
Name of the codec implementation.
Definition: avcodec.h:3488
Format I/O context.
Definition: avformat.h:1342
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1410
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
int width
Definition: frame.h:353
int height
Definition: frame.h:353
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:368
This structure stores compressed data.
Definition: avcodec.h:1454
int stream_index
Definition: avcodec.h:1479
int size
Definition: avcodec.h:1478
uint8_t * data
Definition: avcodec.h:1477
Stream structure.
Definition: avformat.h:870
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1017
static AVCodecContext * decoder_ctx