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demux_decode.c

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1 /*

3 *

4 * Permission is hereby granted, free of charge, to any person obtaining a copy

5 * of this software and associated documentation files (the "Software"), to deal

6 * in the Software without restriction, including without limitation the rights

7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

8 * copies of the Software, and to permit persons to whom the Software is

9 * furnished to do so, subject to the following conditions:

10 *

11 * The above copyright notice and this permission notice shall be included in

12 * all copies or substantial portions of the Software.

13 *

14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

17 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

20 * THE SOFTWARE.

21 */

23 /**

24 * @file libavformat and libavcodec demuxing and decoding API usage example

25 * @example demux_decode.c

26 *

27 * Show how to use the libavformat and libavcodec API to demux and decode audio

28 * and video data. Write the output as raw audio and input files to be played by

29 * ffplay.

30 */

32 #include <libavutil/imgutils.h>

33 #include <libavutil/samplefmt.h>

34 #include <libavutil/timestamp.h>

35 #include <libavcodec/avcodec.h>

36 #include <libavformat/avformat.h>

38 static AVFormatContext *fmt_ctx = NULL;

39 static AVCodecContext *video_dec_ctx = NULL, *audio_dec_ctx;

40 static int width, height;

41 static enum AVPixelFormat pix_fmt;

42 static AVStream *video_stream = NULL, *audio_stream = NULL;

43 static const char *src_filename = NULL;

44 static const char *video_dst_filename = NULL;

45 static const char *audio_dst_filename = NULL;

46 static FILE *video_dst_file = NULL;

47 static FILE *audio_dst_file = NULL;

49 static uint8_t *video_dst_data[4] = {NULL};

50 static int video_dst_linesize[4];

51 static int video_dst_bufsize;

53 static int video_stream_idx = -1, audio_stream_idx = -1;

54 static AVFrame *frame = NULL;

55 static AVPacket *pkt = NULL;

56 static int video_frame_count = 0;

57 static int audio_frame_count = 0;

59 static int output_video_frame(AVFrame *frame)

60 {

61 if (frame->width != width || frame->height != height ||

62 frame->format != pix_fmt) {

63 /* To handle this change, one could call av_image_alloc again and

64 * decode the following frames into another rawvideo file. */

65 fprintf(stderr, "Error: Width, height and pixel format have to be "

66 "constant in a rawvideo file, but the width, height or "

67 "pixel format of the input video changed:\n"

68 "old: width = %d, height = %d, format = %s\n"

69 "new: width = %d, height = %d, format = %s\n",

70 width, height, av_get_pix_fmt_name(pix_fmt),

71 frame->width, frame->height,

72 av_get_pix_fmt_name(frame->format));

73 return -1;

74 }

76 printf("video_frame n:%d\n",

77 video_frame_count++);

79 /* copy decoded frame to destination buffer:

80 * this is required since rawvideo expects non aligned data */

81 av_image_copy2(video_dst_data, video_dst_linesize,

82 frame->data, frame->linesize,

83 pix_fmt, width, height);

85 /* write to rawvideo file */

86 fwrite(video_dst_data[0], 1, video_dst_bufsize, video_dst_file);

87 return 0;

88 }

90 static int output_audio_frame(AVFrame *frame)

91 {

92 size_t unpadded_linesize = frame->nb_samples * av_get_bytes_per_sample(frame->format);

93 printf("audio_frame n:%d nb_samples:%d pts:%s\n",

94 audio_frame_count++, frame->nb_samples,

95 av_ts2timestr(frame->pts, &audio_dec_ctx->time_base));

97 /* Write the raw audio data samples of the first plane. This works

98 * fine for packed formats (e.g. AV_SAMPLE_FMT_S16). However,

99 * most audio decoders output planar audio, which uses a separate

100 * plane of audio samples for each channel (e.g. AV_SAMPLE_FMT_S16P).

101 * In other words, this code will write only the first audio channel

102 * in these cases.

103 * You should use libswresample or libavfilter to convert the frame

104 * to packed data. */

105 fwrite(frame->extended_data[0], 1, unpadded_linesize, audio_dst_file);

106

107 return 0;

108 }

109

110 static int decode_packet(AVCodecContext *dec, const AVPacket *pkt)

111 {

112 int ret = 0;

113

114 // submit the packet to the decoder

115 ret = avcodec_send_packet(dec, pkt);

116 if (ret < 0) {

117 fprintf(stderr, "Error submitting a packet for decoding (%s)\n", av_err2str(ret));

118 return ret;

119 }

120

121 // get all the available frames from the decoder

122 while (ret >= 0) {

123 ret = avcodec_receive_frame(dec, frame);

124 if (ret < 0) {

125 // those two return values are special and mean there is no output

126 // frame available, but there were no errors during decoding

127 if (ret == AVERROR_EOF || ret == AVERROR(EAGAIN))

128 return 0;

129

130 fprintf(stderr, "Error during decoding (%s)\n", av_err2str(ret));

131 return ret;

132 }

133

134 // write the frame data to output file

135 if (dec->codec->type == AVMEDIA_TYPE_VIDEO)

136 ret = output_video_frame(frame);

137 else

138 ret = output_audio_frame(frame);

139

140 av_frame_unref(frame);

141 }

142

143 return ret;

144 }

145

146 static int open_codec_context(int *stream_idx,

147 AVCodecContext **dec_ctx, AVFormatContext *fmt_ctx, enum AVMediaType type)

148 {

149 int ret, stream_index;

150 AVStream *st;

151 const AVCodec *dec = NULL;

152

153 ret = av_find_best_stream(fmt_ctx, type, -1, -1, NULL, 0);

154 if (ret < 0) {

155 fprintf(stderr, "Could not find %s stream in input file '%s'\n",

156 av_get_media_type_string(type), src_filename);

157 return ret;

158 } else {

159 stream_index = ret;

160 st = fmt_ctx->streams[stream_index];

161

162 /* find decoder for the stream */

163 dec = avcodec_find_decoder(st->codecpar->codec_id);

164 if (!dec) {

165 fprintf(stderr, "Failed to find %s codec\n",

166 av_get_media_type_string(type));

167 return AVERROR(EINVAL);

168 }

169

170 /* Allocate a codec context for the decoder */

171 *dec_ctx = avcodec_alloc_context3(dec);

172 if (!*dec_ctx) {

173 fprintf(stderr, "Failed to allocate the %s codec context\n",

174 av_get_media_type_string(type));

175 return AVERROR(ENOMEM);

176 }

177

178 /* Copy codec parameters from input stream to output codec context */

179 if ((ret = avcodec_parameters_to_context(*dec_ctx, st->codecpar)) < 0) {

180 fprintf(stderr, "Failed to copy %s codec parameters to decoder context\n",

181 av_get_media_type_string(type));

182 return ret;

183 }

184

185 /* Init the decoders */

186 if ((ret = avcodec_open2(*dec_ctx, dec, NULL)) < 0) {

187 fprintf(stderr, "Failed to open %s codec\n",

188 av_get_media_type_string(type));

189 return ret;

190 }

191 *stream_idx = stream_index;

192 }

193

194 return 0;

195 }

196

197 static int get_format_from_sample_fmt(const char **fmt,

198 enum AVSampleFormat sample_fmt)

199 {

200 int i;

201 struct sample_fmt_entry {

202 enum AVSampleFormat sample_fmt; const char *fmt_be, *fmt_le;

203 } sample_fmt_entries[] = {

204 { AV_SAMPLE_FMT_U8, "u8", "u8" },

205 { AV_SAMPLE_FMT_S16, "s16be", "s16le" },

206 { AV_SAMPLE_FMT_S32, "s32be", "s32le" },

207 { AV_SAMPLE_FMT_FLT, "f32be", "f32le" },

208 { AV_SAMPLE_FMT_DBL, "f64be", "f64le" },

209 };

210 *fmt = NULL;

211

212 for (i = 0; i < FF_ARRAY_ELEMS(sample_fmt_entries); i++) {

213 struct sample_fmt_entry *entry = &sample_fmt_entries[i];

214 if (sample_fmt == entry->sample_fmt) {

215 *fmt = AV_NE(entry->fmt_be, entry->fmt_le);

216 return 0;

217 }

218 }

219

220 fprintf(stderr,

221 "sample format %s is not supported as output format\n",

222 av_get_sample_fmt_name(sample_fmt));

223 return -1;

224 }

225

226 int main (int argc, char **argv)

227 {

228 int ret = 0;

229

230 if (argc != 4) {

231 fprintf(stderr, "usage: %s input_file video_output_file audio_output_file\n"

232 "API example program to show how to read frames from an input file.\n"

233 "This program reads frames from a file, decodes them, and writes decoded\n"

234 "video frames to a rawvideo file named video_output_file, and decoded\n"

235 "audio frames to a rawaudio file named audio_output_file.\n",

236 argv[0]);

237 exit(1);

238 }

239 src_filename = argv[1];

240 video_dst_filename = argv[2];

241 audio_dst_filename = argv[3];

242

243 /* open input file, and allocate format context */

244 if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) < 0) {

245 fprintf(stderr, "Could not open source file %s\n", src_filename);

246 exit(1);

247 }

248

249 /* retrieve stream information */

250 if (avformat_find_stream_info(fmt_ctx, NULL) < 0) {

251 fprintf(stderr, "Could not find stream information\n");

252 exit(1);

253 }

254

255 if (open_codec_context(&video_stream_idx, &video_dec_ctx, fmt_ctx, AVMEDIA_TYPE_VIDEO) >= 0) {

256 video_stream = fmt_ctx->streams[video_stream_idx];

257

258 video_dst_file = fopen(video_dst_filename, "wb");

259 if (!video_dst_file) {

260 fprintf(stderr, "Could not open destination file %s\n", video_dst_filename);

261 ret = 1;

262 goto end;

263 }

264

265 /* allocate image where the decoded image will be put */

266 width = video_dec_ctx->width;

267 height = video_dec_ctx->height;

268 pix_fmt = video_dec_ctx->pix_fmt;

269 ret = av_image_alloc(video_dst_data, video_dst_linesize,

270 width, height, pix_fmt, 1);

271 if (ret < 0) {

272 fprintf(stderr, "Could not allocate raw video buffer\n");

273 goto end;

274 }

275 video_dst_bufsize = ret;

276 }

277

278 if (open_codec_context(&audio_stream_idx, &audio_dec_ctx, fmt_ctx, AVMEDIA_TYPE_AUDIO) >= 0) {

279 audio_stream = fmt_ctx->streams[audio_stream_idx];

280 audio_dst_file = fopen(audio_dst_filename, "wb");

281 if (!audio_dst_file) {

282 fprintf(stderr, "Could not open destination file %s\n", audio_dst_filename);

283 ret = 1;

284 goto end;

285 }

286 }

287

288 /* dump input information to stderr */

289 av_dump_format(fmt_ctx, 0, src_filename, 0);

290

291 if (!audio_stream && !video_stream) {

292 fprintf(stderr, "Could not find audio or video stream in the input, aborting\n");

293 ret = 1;

294 goto end;

295 }

296

297 frame = av_frame_alloc();

298 if (!frame) {

299 fprintf(stderr, "Could not allocate frame\n");

300 ret = AVERROR(ENOMEM);

301 goto end;

302 }

303

304 pkt = av_packet_alloc();

305 if (!pkt) {

306 fprintf(stderr, "Could not allocate packet\n");

307 ret = AVERROR(ENOMEM);

308 goto end;

309 }

310

311 if (video_stream)

312 printf("Demuxing video from file '%s' into '%s'\n", src_filename, video_dst_filename);

313 if (audio_stream)

314 printf("Demuxing audio from file '%s' into '%s'\n", src_filename, audio_dst_filename);

315

316 /* read frames from the file */

317 while (av_read_frame(fmt_ctx, pkt) >= 0) {

318 // check if the packet belongs to a stream we are interested in, otherwise

319 // skip it

320 if (pkt->stream_index == video_stream_idx)

321 ret = decode_packet(video_dec_ctx, pkt);

322 else if (pkt->stream_index == audio_stream_idx)

323 ret = decode_packet(audio_dec_ctx, pkt);

324 av_packet_unref(pkt);

325 if (ret < 0)

326 break;

327 }

328

329 /* flush the decoders */

330 if (video_dec_ctx)

331 decode_packet(video_dec_ctx, NULL);

332 if (audio_dec_ctx)

333 decode_packet(audio_dec_ctx, NULL);

334

335 printf("Demuxing succeeded.\n");

336

337 if (video_stream) {

338 printf("Play the output video file with the command:\n"

339 "ffplay -f rawvideo -pix_fmt %s -video_size %dx%d %s\n",

340 av_get_pix_fmt_name(pix_fmt), width, height,

341 video_dst_filename);

342 }

343

344 if (audio_stream) {

345 enum AVSampleFormat sfmt = audio_dec_ctx->sample_fmt;

346 int n_channels = audio_dec_ctx->ch_layout.nb_channels;

347 const char *fmt;

348

349 if (av_sample_fmt_is_planar(sfmt)) {

350 const char *packed = av_get_sample_fmt_name(sfmt);

351 printf("Warning: the sample format the decoder produced is planar "

352 "(%s). This example will output the first channel only.\n",

353 packed ? packed : "?");

354 sfmt = av_get_packed_sample_fmt(sfmt);

355 n_channels = 1;

356 }

357

358 if ((ret = get_format_from_sample_fmt(&fmt, sfmt)) < 0)

359 goto end;

360

361 printf("Play the output audio file with the command:\n"

362 "ffplay -f %s -ac %d -ar %d %s\n",

363 fmt, n_channels, audio_dec_ctx->sample_rate,

364 audio_dst_filename);

365 }

366

367 end:

368 avcodec_free_context(&video_dec_ctx);

369 avcodec_free_context(&audio_dec_ctx);

370 avformat_close_input(&fmt_ctx);

371 if (video_dst_file)

372 fclose(video_dst_file);

373 if (audio_dst_file)

374 fclose(audio_dst_file);

375 av_packet_free(&pkt);

376 av_frame_free(&frame);

377 av_free(video_dst_data[0]);

378

379 return ret < 0;

380 }

av_packet_unref

void av_packet_unref(AVPacket *pkt)

Wipe the packet.

Definition: avpacket.c:427

AVCodec

AVCodec.

Definition: codec.h:187

AVPixelFormat

Pixel format.

Definition: pixfmt.h:71

entry

#define entry

Definition: aom_film_grain_template.c:66

dec_ctx

static AVCodecContext * dec_ctx

Definition: decode_filter_audio.c:46

AVERROR

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

av_find_best_stream

int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type, int wanted_stream_nb, int related_stream, const AVCodec **decoder_ret, int flags)

Definition: avformat.c:443

AVCodecContext::sample_rate

int sample_rate

samples per second

Definition: avcodec.h:1050

AVERROR_EOF

#define AVERROR_EOF

End of file.

Definition: error.h:57

av_frame_free

void av_frame_free(AVFrame **frame)

Free the frame and any dynamically allocated objects in it, e.g.

Definition: frame.c:130

AVFrame

This structure describes decoded (raw) audio or video data.

Definition: frame.h:344

AVFormatContext::streams

AVStream ** streams

A list of all streams in the file.

Definition: avformat.h:1323

AVFrame::pts

int64_t pts

Presentation timestamp in time_base units (time when frame should be shown to user).

Definition: frame.h:456

AVFrame::width

int width

Definition: frame.h:416

output_video_frame

static int output_video_frame(AVFrame *frame)

Definition: demux_decode.c:59

get_format_from_sample_fmt

static int get_format_from_sample_fmt(const char **fmt, enum AVSampleFormat sample_fmt)

Definition: demux_decode.c:197

decode_packet

static int decode_packet(AVCodecContext *dec, const AVPacket *pkt)

Definition: demux_decode.c:110

av_read_frame

int av_read_frame(AVFormatContext *s, AVPacket *pkt)

Return the next frame of a stream.

Definition: demux.c:1525

AVChannelLayout::nb_channels

int nb_channels

Number of channels in this layout.

Definition: channel_layout.h:313

av_packet_free

void av_packet_free(AVPacket **pkt)

Free the packet, if the packet is reference counted, it will be unreferenced first.

Definition: avpacket.c:74

AVFrame::data

uint8_t * data[AV_NUM_DATA_POINTERS]

pointer to the picture/channel planes.

Definition: frame.h:365

video_dst_filename

static const char * video_dst_filename

Definition: demux_decode.c:44

avformat_close_input

void avformat_close_input(AVFormatContext **s)

Close an opened input AVFormatContext.

Definition: demux.c:362

AVCodecContext::codec

const struct AVCodec * codec

Definition: avcodec.h:454

AVCodecContext::ch_layout

AVChannelLayout ch_layout

Audio channel layout.

Definition: avcodec.h:1065

audio_stream_idx

static int audio_stream_idx

Definition: demux_decode.c:53

samplefmt.h

audio_dst_file

static FILE * audio_dst_file

Definition: demux_decode.c:47

src_filename

static const char * src_filename

Definition: demux_decode.c:43

type

it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type

Definition: writing_filters.txt:86

av_frame_alloc

AVFrame * av_frame_alloc(void)

Allocate an AVFrame and set its fields to default values.

Definition: frame.c:118

FF_ARRAY_ELEMS

#define FF_ARRAY_ELEMS(a)

Definition: sinewin_tablegen.c:29

av_dump_format

void av_dump_format(AVFormatContext *ic, int index, const char *url, int is_output)

Print detailed information about the input or output format, such as duration, bitrate,...

Definition: dump.c:760

avformat_open_input

int avformat_open_input(AVFormatContext **ps, const char *url, const AVInputFormat *fmt, AVDictionary **options)

Open an input stream and read the header.

Definition: demux.c:214

avcodec_alloc_context3

AVCodecContext * avcodec_alloc_context3(const AVCodec *codec)

Allocate an AVCodecContext and set its fields to default values.

Definition: options.c:149

AV_NE

#define AV_NE(be, le)

Definition: macros.h:33

pix_fmt

static enum AVPixelFormat pix_fmt

Definition: demux_decode.c:41

AVMEDIA_TYPE_AUDIO

@ AVMEDIA_TYPE_AUDIO

Definition: avutil.h:202

video_stream

static AVStream * video_stream

Definition: demux_decode.c:42

video_dst_file

static FILE * video_dst_file

Definition: demux_decode.c:46

audio_frame_count

static int audio_frame_count

Definition: demux_decode.c:57

avcodec_receive_frame

int attribute_align_arg 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...

Definition: avcodec.c:681

av_sample_fmt_is_planar

int av_sample_fmt_is_planar(enum AVSampleFormat sample_fmt)

Check if the sample format is planar.

Definition: samplefmt.c:114

audio_dec_ctx

static AVCodecContext * audio_dec_ctx

Definition: demux_decode.c:39

av_get_sample_fmt_name

const char * av_get_sample_fmt_name(enum AVSampleFormat sample_fmt)

Return the name of sample_fmt, or NULL if sample_fmt is not recognized.

Definition: samplefmt.c:51

frame

static AVFrame * frame

Definition: demux_decode.c:54

video_stream_idx

static int video_stream_idx

Definition: demux_decode.c:53

AVFormatContext

Format I/O context.

Definition: avformat.h:1255

AVStream::codecpar

AVCodecParameters * codecpar

Codec parameters associated with this stream.

Definition: avformat.h:766

avcodec_parameters_to_context

int avcodec_parameters_to_context(AVCodecContext *codec, const struct AVCodecParameters *par)

Fill the codec context based on the values from the supplied codec parameters.

NULL

#define NULL

Definition: coverity.c:32

AVCodec::type

enum AVMediaType type

Definition: codec.h:200

avcodec_free_context

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:164

avcodec_open2

int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *codec, AVDictionary **options)

Initialize the AVCodecContext to use the given AVCodec.

Definition: avcodec.c:128

avcodec_find_decoder

const AVCodec * avcodec_find_decoder(enum AVCodecID id)

Find a registered decoder with a matching codec ID.

Definition: allcodecs.c:971

av_image_alloc

int av_image_alloc(uint8_t *pointers[4], int linesizes[4], int w, int h, enum AVPixelFormat pix_fmt, int align)

Allocate an image with size w and h and pixel format pix_fmt, and fill pointers and linesizes accordi...

Definition: imgutils.c:218

AVCodecContext::time_base

AVRational time_base

This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented.

Definition: avcodec.h:544

avformat_find_stream_info

int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)

Read packets of a media file to get stream information.

Definition: demux.c:2499

av_ts2timestr

#define av_ts2timestr(ts, tb)

Convenience macro, the return value should be used only directly in function arguments but never stan...

Definition: timestamp.h:83

AVMediaType

Definition: avutil.h:199

av_err2str

#define av_err2str(errnum)

Convenience macro, the return value should be used only directly in function arguments but never stan...

Definition: error.h:121

audio_dst_filename

static const char * audio_dst_filename

Definition: demux_decode.c:45

audio_stream

static AVStream * audio_stream

Definition: demux_decode.c:42

AVCodecContext::sample_fmt

enum AVSampleFormat sample_fmt

audio sample format

Definition: avcodec.h:1057

video_dst_linesize

static int video_dst_linesize[4]

Definition: demux_decode.c:50

printf

printf("static const uint8_t my_array[100] = {\n")

AVFrame::format

int format

format of the frame, -1 if unknown or unset Values correspond to enum AVPixelFormat for video frames,...

Definition: frame.h:431

fmt_ctx

static AVFormatContext * fmt_ctx

Definition: demux_decode.c:38

av_packet_alloc

AVPacket * av_packet_alloc(void)

Allocate an AVPacket and set its fields to default values.

Definition: avpacket.c:63

avcodec_send_packet

int avcodec_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)

Supply raw packet data as input to a decoder.

Definition: decode.c:675

AVFrame::nb_samples

int nb_samples

number of audio samples (per channel) described by this frame

Definition: frame.h:424

#define i(width, name, range_min, range_max)

Definition: cbs_h2645.c:255

av_get_bytes_per_sample

int av_get_bytes_per_sample(enum AVSampleFormat sample_fmt)

Return number of bytes per sample.

Definition: samplefmt.c:108

AV_SAMPLE_FMT_U8

@ AV_SAMPLE_FMT_U8

unsigned 8 bits

Definition: samplefmt.h:57

AVFrame::extended_data

uint8_t ** extended_data

pointers to the data planes/channels.

Definition: frame.h:405

AVSampleFormat

Audio sample formats.

Definition: samplefmt.h:55

av_frame_unref

void av_frame_unref(AVFrame *frame)

Unreference all the buffers referenced by frame and reset the frame fields.

Definition: frame.c:576

AV_SAMPLE_FMT_S16

@ AV_SAMPLE_FMT_S16

signed 16 bits

Definition: samplefmt.h:58

video_dst_data

static uint8_t * video_dst_data[4]

Definition: demux_decode.c:49

open_codec_context

static int open_codec_context(int *stream_idx, AVCodecContext **dec_ctx, AVFormatContext *fmt_ctx, enum AVMediaType type)

Definition: demux_decode.c:146

AVCodecContext::height

int height

Definition: avcodec.h:618

AVCodecContext::pix_fmt

enum AVPixelFormat pix_fmt

Pixel format, see AV_PIX_FMT_xxx.

Definition: avcodec.h:657

avcodec.h

ret

Definition: filter_design.txt:187

AVStream

Stream structure.

Definition: avformat.h:743

avformat.h

av_get_media_type_string

const char * av_get_media_type_string(enum AVMediaType media_type)

Return a string describing the media_type enum, NULL if media_type is unknown.

Definition: utils.c:28

AVCodecContext

main external API structure.

Definition: avcodec.h:445

AVFrame::height

int height

Definition: frame.h:416

av_image_copy2

static void av_image_copy2(uint8_t *const dst_data[4], const int dst_linesizes[4], uint8_t *const src_data[4], const int src_linesizes[4], enum AVPixelFormat pix_fmt, int width, int height)

Wrapper around av_image_copy() to workaround the limitation that the conversion from uint8_t * const ...

Definition: imgutils.h:184

width

static int width

Definition: demux_decode.c:40

av_get_packed_sample_fmt

enum AVSampleFormat av_get_packed_sample_fmt(enum AVSampleFormat sample_fmt)

Get the packed alternative form of the given sample format.

Definition: samplefmt.c:77

AVPacket::stream_index

int stream_index

Definition: packet.h:524