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
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>
38 #include <libavformat/avformat.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 
47 static FILE *output_file = NULL;
48 
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  }
58  ctx->hw_device_ctx = av_buffer_ref(hw_device_ctx);
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 
77 static 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) {
100  av_frame_free(&frame);
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:
141  av_frame_free(&frame);
142  av_frame_free(&sw_frame);
143  av_freep(&buffer);
144  if (ret < 0)
145  return ret;
146  }
147 }
148 
149 int 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];
212  if (avcodec_parameters_to_context(decoder_ctx, video->codecpar) < 0)
213  return -1;
214 
215  decoder_ctx->get_format = get_hw_format;
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);
247  avcodec_free_context(&decoder_ctx);
248  avformat_close_input(&input_ctx);
249  av_buffer_unref(&hw_device_ctx);
250 
251  return 0;
252 }
enum AVPixelFormat(* get_format)(struct AVCodecContext *s, const enum AVPixelFormat *fmt)
callback to negotiate the pixelFormat
Definition: avcodec.h:1817
#define NULL
Definition: coverity.c:32
void av_buffer_unref(AVBufferRef **buf)
Free a given reference and automatically free the buffer if there are no more references to it...
Definition: buffer.c:125
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
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.
Definition: imgutils.c:453
static enum AVPixelFormat get_hw_format(AVCodecContext *ctx, const enum AVPixelFormat *pix_fmts)
Definition: hw_decode.c:63
misc image utilities
enum AVHWDeviceType av_hwdevice_find_type_by_name(const char *name)
Look up an AVHWDeviceType by name.
Definition: hwcontext.c:78
static AVCodecContext * decoder_ctx
int size
Definition: avcodec.h:1478
static AVStream * video_stream
GLint GLenum type
Definition: opengl_enc.c:104
int avformat_open_input(AVFormatContext **ps, const char *url, ff_const59 AVInputFormat *fmt, AVDictionary **options)
Open an input stream and read the header.
Definition: utils.c:537
AVCodec.
Definition: avcodec.h:3481
Format I/O context.
Definition: avformat.h:1358
uint8_t
#define av_malloc(s)
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:189
AVOptions.
The codec supports this format via the hw_device_ctx interface.
Definition: avcodec.h:3427
enum AVPixelFormat pix_fmt
A hardware pixel format which the codec can use.
Definition: avcodec.h:3459
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
int avcodec_parameters_to_context(AVCodecContext *codec, const AVCodecParameters *par)
Fill the codec context based on the values from the supplied codec parameters.
Definition: utils.c:2096
int av_hwdevice_ctx_create(AVBufferRef **pdevice_ref, enum AVHWDeviceType type, const char *device, AVDictionary *opts, int flags)
Open a device of the specified type and create an AVHWDeviceContext for it.
Definition: hwcontext.c:571
uint8_t * data
Definition: avcodec.h:1477
#define AVERROR_EOF
End of file.
Definition: error.h:55
ptrdiff_t size
Definition: opengl_enc.c:100
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.
Definition: utils.c:4192
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...
Definition: imgutils.c:431
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
int width
Definition: frame.h:353
static AVBufferRef * hw_device_ctx
Definition: hw_decode.c:45
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
int methods
Bit set of AV_CODEC_HW_CONFIG_METHOD_* flags, describing the possible setup methods which can be used...
Definition: avcodec.h:3464
int avcodec_receive_frame(AVCodecContext *avctx, AVFrame *frame)
Return decoded output data from a decoder.
Definition: decode.c:740
int main(int argc, char *argv[])
Definition: hw_decode.c:149
simple assert() macros that are a bit more flexible than ISO C assert().
const char * name
Name of the codec implementation.
Definition: avcodec.h:3488
#define fail()
Definition: checkasm.h:120
int av_hwframe_transfer_data(AVFrame *dst, const AVFrame *src, int flags)
Copy data to or from a hw surface.
Definition: hwcontext.c:439
AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)
Allocate an AVCodecContext and set its fields to default values.
Definition: options.c:156
static const chunk_decoder decoder[8]
Definition: dfa.c:330
AVFormatContext * ctx
Definition: movenc.c:48
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Stream structure.
Definition: avformat.h:881
int format
format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames...
Definition: frame.h:368
static FILE * output_file
Definition: hw_decode.c:47
int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)
Supply raw packet data as input to a decoder.
Definition: decode.c:677
Libavcodec external API header.
static int hw_decoder_init(AVCodecContext *ctx, const enum AVHWDeviceType type)
Definition: hw_decode.c:49
void avcodec_free_context(AVCodecContext **avctx)
Free the codec context and everything associated with it and write NULL to the provided pointer...
Definition: options.c:171
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
const AVCodecHWConfig * avcodec_get_hw_config(const AVCodec *codec, int index)
Retrieve supported hardware configurations for a codec.
Definition: utils.c:1765
main external API structure.
Definition: avcodec.h:1565
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:599
static int decode_write(AVCodecContext *avctx, AVPacket *packet)
Definition: hw_decode.c:77
const char * av_hwdevice_get_type_name(enum AVHWDeviceType type)
Get the string name of an AVHWDeviceType.
Definition: hwcontext.c:88
int avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options)
Initialize the AVCodecContext to use the given AVCodec.
Definition: utils.c:542
int av_read_frame(AVFormatContext *s, AVPacket *pkt)
Return the next frame of a stream.
Definition: utils.c:1768
static enum AVPixelFormat pix_fmts[]
Definition: libkvazaar.c:275
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
A reference to a data buffer.
Definition: buffer.h:81
Main libavformat public API header.
static enum AVPixelFormat hw_pix_fmt
Definition: hw_decode.c:46
int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
Read packets of a media file to get stream information.
Definition: utils.c:3573
AVBufferRef * av_buffer_ref(AVBufferRef *buf)
Create a new reference to an AVBuffer.
Definition: buffer.c:93
void avformat_close_input(AVFormatContext **s)
Close an opened input AVFormatContext.
Definition: utils.c:4437
enum AVHWDeviceType av_hwdevice_iterate_types(enum AVHWDeviceType prev)
Iterate over supported device types.
Definition: hwcontext.c:97
A Quick Description Of Rate Distortion Theory We want to encode a video
AVHWDeviceType
Definition: hwcontext.h:27
int height
Definition: frame.h:353
#define av_freep(p)
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
enum AVHWDeviceType device_type
The device type associated with the configuration.
Definition: avcodec.h:3471
int stream_index
Definition: avcodec.h:1479
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
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
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
This structure stores compressed data.
Definition: avcodec.h:1454
GLuint buffer
Definition: opengl_enc.c:101