FFmpeg
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>
37 #include <libavformat/avformat.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 
44 static AVBufferRef *hw_device_ctx = NULL;
45 static enum AVPixelFormat hw_pix_fmt;
46 static FILE *output_file = NULL;
47 
48 static 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 
76 static 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 
148 int main(int argc, char *argv[])
149 {
150  AVFormatContext *input_ctx = NULL;
151  int video_stream, ret;
152  AVStream *video = NULL;
153  AVCodecContext *decoder_ctx = 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.
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.
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
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:306
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 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.
unsigned size
allocated memory
Definition: bprint.h:99
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.
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
const char * av_hwdevice_get_type_name(enum AVHWDeviceType type)
Get the string name of an AVHWDeviceType.
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:426
enum AVPixelFormat(* get_format)(struct AVCodecContext *s, const enum AVPixelFormat *fmt)
Callback to negotiate the pixel format.
Definition: avcodec.h:689
AVBufferRef * hw_device_ctx
A reference to the AVHWDeviceContext describing the device which will be used by a hardware encoder/d...
Definition: avcodec.h:1928
enum AVHWDeviceType device_type
The device type associated with the configuration.
Definition: codec.h:359
int methods
Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible setup methods which can be used...
Definition: codec.h:352
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:347
AVCodec.
Definition: codec.h:184
const char * name
Name of the codec implementation.
Definition: codec.h:191
Format I/O context.
Definition: avformat.h:1104
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1172
This structure describes decoded (raw) audio or video data.
Definition: frame.h:330
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:351
int width
Definition: frame.h:402
int height
Definition: frame.h:402
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:375
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...
Definition: frame.h:417
This structure stores compressed data.
Definition: packet.h:351
int stream_index
Definition: packet.h:376
Stream structure.
Definition: avformat.h:838
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:861
static AVCodecContext * decoder_ctx