FFmpeg 6.1.1
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 HW-accelerated decoding API usage.example
28 * @example hw_decode.c
29 *
30 * Perform HW-accelerated decoding with output frames from HW video
31 * surfaces.
32 */
33
34#include <stdio.h>
35
36#include <libavcodec/avcodec.h>
38#include <libavutil/pixdesc.h>
39#include <libavutil/hwcontext.h>
40#include <libavutil/opt.h>
41#include <libavutil/avassert.h>
42#include <libavutil/imgutils.h>
43
46static FILE *output_file = NULL;
47
48static int hw_decoder_init(AVCodecContext *ctx, const enum AVHWDeviceType type)
49{
50 int err = 0;
51
52 if ((err = av_hwdevice_ctx_create(&hw_device_ctx, type,
53 NULL, NULL, 0)) < 0) {
54 fprintf(stderr, "Failed to create specified HW device.\n");
55 return err;
56 }
58
59 return err;
60}
61
63 const enum AVPixelFormat *pix_fmts)
64{
65 const enum AVPixelFormat *p;
66
67 for (p = pix_fmts; *p != -1; p++) {
68 if (*p == hw_pix_fmt)
69 return *p;
70 }
71
72 fprintf(stderr, "Failed to get HW surface format.\n");
73 return AV_PIX_FMT_NONE;
74}
75
76static int decode_write(AVCodecContext *avctx, AVPacket *packet)
77{
78 AVFrame *frame = NULL, *sw_frame = NULL;
79 AVFrame *tmp_frame = NULL;
80 uint8_t *buffer = NULL;
81 int size;
82 int ret = 0;
83
84 ret = avcodec_send_packet(avctx, packet);
85 if (ret < 0) {
86 fprintf(stderr, "Error during decoding\n");
87 return ret;
88 }
89
90 while (1) {
91 if (!(frame = av_frame_alloc()) || !(sw_frame = av_frame_alloc())) {
92 fprintf(stderr, "Can not alloc frame\n");
93 ret = AVERROR(ENOMEM);
94 goto fail;
95 }
96
97 ret = avcodec_receive_frame(avctx, frame);
98 if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
100 av_frame_free(&sw_frame);
101 return 0;
102 } else if (ret < 0) {
103 fprintf(stderr, "Error while decoding\n");
104 goto fail;
105 }
106
107 if (frame->format == hw_pix_fmt) {
108 /* retrieve data from GPU to CPU */
109 if ((ret = av_hwframe_transfer_data(sw_frame, frame, 0)) < 0) {
110 fprintf(stderr, "Error transferring the data to system memory\n");
111 goto fail;
112 }
113 tmp_frame = sw_frame;
114 } else
115 tmp_frame = frame;
116
117 size = av_image_get_buffer_size(tmp_frame->format, tmp_frame->width,
118 tmp_frame->height, 1);
119 buffer = av_malloc(size);
120 if (!buffer) {
121 fprintf(stderr, "Can not alloc buffer\n");
122 ret = AVERROR(ENOMEM);
123 goto fail;
124 }
125 ret = av_image_copy_to_buffer(buffer, size,
126 (const uint8_t * const *)tmp_frame->data,
127 (const int *)tmp_frame->linesize, tmp_frame->format,
128 tmp_frame->width, tmp_frame->height, 1);
129 if (ret < 0) {
130 fprintf(stderr, "Can not copy image to buffer\n");
131 goto fail;
132 }
133
134 if ((ret = fwrite(buffer, 1, size, output_file)) < 0) {
135 fprintf(stderr, "Failed to dump raw data.\n");
136 goto fail;
137 }
138
139 fail:
141 av_frame_free(&sw_frame);
142 av_freep(&buffer);
143 if (ret < 0)
144 return ret;
145 }
146}
147
148int main(int argc, char *argv[])
149{
150 AVFormatContext *input_ctx = NULL;
151 int video_stream, ret;
152 AVStream *video = NULL;
154 const AVCodec *decoder = NULL;
155 AVPacket *packet = NULL;
156 enum AVHWDeviceType type;
157 int i;
158
159 if (argc < 4) {
160 fprintf(stderr, "Usage: %s <device type> <input file> <output file>\n", argv[0]);
161 return -1;
162 }
163
164 type = av_hwdevice_find_type_by_name(argv[1]);
165 if (type == AV_HWDEVICE_TYPE_NONE) {
166 fprintf(stderr, "Device type %s is not supported.\n", argv[1]);
167 fprintf(stderr, "Available device types:");
168 while((type = av_hwdevice_iterate_types(type)) != AV_HWDEVICE_TYPE_NONE)
169 fprintf(stderr, " %s", av_hwdevice_get_type_name(type));
170 fprintf(stderr, "\n");
171 return -1;
172 }
173
174 packet = av_packet_alloc();
175 if (!packet) {
176 fprintf(stderr, "Failed to allocate AVPacket\n");
177 return -1;
178 }
179
180 /* open the input file */
181 if (avformat_open_input(&input_ctx, argv[2], NULL, NULL) != 0) {
182 fprintf(stderr, "Cannot open input file '%s'\n", argv[2]);
183 return -1;
184 }
185
186 if (avformat_find_stream_info(input_ctx, NULL) < 0) {
187 fprintf(stderr, "Cannot find input stream information.\n");
188 return -1;
189 }
190
191 /* find the video stream information */
192 ret = av_find_best_stream(input_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &decoder, 0);
193 if (ret < 0) {
194 fprintf(stderr, "Cannot find a video stream in the input file\n");
195 return -1;
196 }
197 video_stream = ret;
198
199 for (i = 0;; i++) {
200 const AVCodecHWConfig *config = avcodec_get_hw_config(decoder, i);
201 if (!config) {
202 fprintf(stderr, "Decoder %s does not support device type %s.\n",
203 decoder->name, av_hwdevice_get_type_name(type));
204 return -1;
205 }
207 config->device_type == type) {
208 hw_pix_fmt = config->pix_fmt;
209 break;
210 }
211 }
212
213 if (!(decoder_ctx = avcodec_alloc_context3(decoder)))
214 return AVERROR(ENOMEM);
215
216 video = input_ctx->streams[video_stream];
218 return -1;
219
221
222 if (hw_decoder_init(decoder_ctx, type) < 0)
223 return -1;
224
225 if ((ret = avcodec_open2(decoder_ctx, decoder, NULL)) < 0) {
226 fprintf(stderr, "Failed to open codec for stream #%u\n", video_stream);
227 return -1;
228 }
229
230 /* open the file to dump raw data */
231 output_file = fopen(argv[3], "w+b");
232
233 /* actual decoding and dump the raw data */
234 while (ret >= 0) {
235 if ((ret = av_read_frame(input_ctx, packet)) < 0)
236 break;
237
238 if (video_stream == packet->stream_index)
239 ret = decode_write(decoder_ctx, packet);
240
241 av_packet_unref(packet);
242 }
243
244 /* flush the decoder */
245 ret = decode_write(decoder_ctx, NULL);
246
247 if (output_file)
248 fclose(output_file);
249 av_packet_free(&packet);
251 avformat_close_input(&input_ctx);
253
254 return 0;
255}
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
Definition: demux_decode.c:42
static AVFrame * frame
Definition: demux_decode.c:54
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.
int avcodec_parameters_to_context(AVCodecContext *codec, const struct AVCodecParameters *par)
Fill the codec context based on the values from the supplied codec parameters.
const AVCodecHWConfig * avcodec_get_hw_config(const AVCodec *codec, int index)
Retrieve supported hardware configurations for a codec.
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: codec.h:309
int avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame)
Return decoded output data from a decoder or encoder (when the AV_CODEC_FLAG_RECON_FRAME flag is used...
int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)
Supply raw packet data as input to a decoder.
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to default values.
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, const struct AVCodec **decoder_ret, int flags)
Find the "best" stream in the file.
int avformat_open_input(AVFormatContext **ps, const char *url, const AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
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.
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(const AVBufferRef *buf)
Create a new reference to an AVBuffer.
#define AVERROR_EOF
End of file.
Definition: error.h:57
#define AVERROR(e)
Definition: error.h:45
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:48
static AVBufferRef * hw_device_ctx
Definition: hw_decode.c:44
int main(int argc, char *argv[])
Definition: hw_decode.c:148
static FILE * output_file
Definition: hw_decode.c:46
static enum AVPixelFormat hw_pix_fmt
Definition: hw_decode.c:45
static int decode_write(AVCodecContext *avctx, AVPacket *packet)
Definition: hw_decode.c:76
static enum AVPixelFormat get_hw_format(AVCodecContext *ctx, const enum AVPixelFormat *pix_fmts)
Definition: hw_decode.c:62
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:82
main external API structure.
Definition: avcodec.h:441
enum AVPixelFormat(* get_format)(struct AVCodecContext *s, const enum AVPixelFormat *fmt)
Callback to negotiate the pixel format.
Definition: avcodec.h:712
AVBufferRef * hw_device_ctx
A reference to the AVHWDeviceContext describing the device which will be used by a hardware encoder/d...
Definition: avcodec.h:1981
enum AVHWDeviceType device_type
The device type associated with the configuration.
Definition: codec.h:362
int methods
Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible setup methods which can be used...
Definition: codec.h:355
enum AVPixelFormat pix_fmt
For decoders, a hardware pixel format which that decoder may be able to decode to if suitable hardwar...
Definition: codec.h:350
AVCodec.
Definition: codec.h:187
const char * name
Name of the codec implementation.
Definition: codec.h:194
Format I/O context.
Definition: avformat.h:1115
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1183
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:361
int width
Definition: frame.h:412
int height
Definition: frame.h:412
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:385
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:427
This structure stores compressed data.
Definition: packet.h:468
int stream_index
Definition: packet.h:493
Stream structure.
Definition: avformat.h:841
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:864
static AVCodecContext * decoder_ctx