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| 1 | +/* | |
| 2 | + * Copyright (c) 2001 Fabrice Bellard | |
| 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 | + */ | |
| 22 | + | |
| 23 | +/** | |
| 24 | + * @file | |
| 25 | + * libavcodec API use example. | |
| 26 | + * | |
| 27 | + * @example decoding_encoding.c | |
| 28 | + * Note that libavcodec only handles codecs (mpeg, mpeg4, etc...), | |
| 29 | + * not file formats (avi, vob, mp4, mov, mkv, mxf, flv, mpegts, mpegps, etc...). See library 'libavformat' for the | |
| 30 | + * format handling | |
| 31 | + */ | |
| 32 | + | |
| 33 | +#include <math.h> | |
| 34 | + | |
| 35 | +#include <libavutil/opt.h> | |
| 36 | +#include <libavcodec/avcodec.h> | |
| 37 | +#include <libavutil/channel_layout.h> | |
| 38 | +#include <libavutil/common.h> | |
| 39 | +#include <libavutil/imgutils.h> | |
| 40 | +#include <libavutil/mathematics.h> | |
| 41 | +#include <libavutil/samplefmt.h> | |
| 42 | + | |
| 43 | +#define INBUF_SIZE 4096 | |
| 44 | +#define AUDIO_INBUF_SIZE 20480 | |
| 45 | +#define AUDIO_REFILL_THRESH 4096 | |
| 46 | + | |
| 47 | +/* check that a given sample format is supported by the encoder */ | |
| 48 | +static int check_sample_fmt(AVCodec *codec, enum AVSampleFormat sample_fmt) | |
| 49 | +{ | |
| 50 | + const enum AVSampleFormat *p = codec->sample_fmts; | |
| 51 | + | |
| 52 | + while (*p != AV_SAMPLE_FMT_NONE) { | |
| 53 | + if (*p == sample_fmt) | |
| 54 | + return 1; | |
| 55 | + p++; | |
| 56 | + } | |
| 57 | + return 0; | |
| 58 | +} | |
| 59 | + | |
| 60 | +/* just pick the highest supported samplerate */ | |
| 61 | +static int select_sample_rate(AVCodec *codec) | |
| 62 | +{ | |
| 63 | + const int *p; | |
| 64 | + int best_samplerate = 0; | |
| 65 | + | |
| 66 | + if (!codec->supported_samplerates) | |
| 67 | + return 44100; | |
| 68 | + | |
| 69 | + p = codec->supported_samplerates; | |
| 70 | + while (*p) { | |
| 71 | + best_samplerate = FFMAX(*p, best_samplerate); | |
| 72 | + p++; | |
| 73 | + } | |
| 74 | + return best_samplerate; | |
| 75 | +} | |
| 76 | + | |
| 77 | +/* select layout with the highest channel count */ | |
| 78 | +static int select_channel_layout(AVCodec *codec) | |
| 79 | +{ | |
| 80 | + const uint64_t *p; | |
| 81 | + uint64_t best_ch_layout = 0; | |
| 82 | + int best_nb_channels = 0; | |
| 83 | + | |
| 84 | + if (!codec->channel_layouts) | |
| 85 | + return AV_CH_LAYOUT_STEREO; | |
| 86 | + | |
| 87 | + p = codec->channel_layouts; | |
| 88 | + while (*p) { | |
| 89 | + int nb_channels = av_get_channel_layout_nb_channels(*p); | |
| 90 | + | |
| 91 | + if (nb_channels > best_nb_channels) { | |
| 92 | + best_ch_layout = *p; | |
| 93 | + best_nb_channels = nb_channels; | |
| 94 | + } | |
| 95 | + p++; | |
| 96 | + } | |
| 97 | + return best_ch_layout; | |
| 98 | +} | |
| 99 | + | |
| 100 | +/* | |
| 101 | + * Audio encoding example | |
| 102 | + */ | |
| 103 | +static void audio_encode_example(const char *filename) | |
| 104 | +{ | |
| 105 | + AVCodec *codec; | |
| 106 | + AVCodecContext *c= NULL; | |
| 107 | + AVFrame *frame; | |
| 108 | + AVPacket pkt; | |
| 109 | + int i, j, k, ret, got_output; | |
| 110 | + int buffer_size; | |
| 111 | + FILE *f; | |
| 112 | + uint16_t *samples; | |
| 113 | + float t, tincr; | |
| 114 | + | |
| 115 | + printf("Encode audio file %s\n", filename); | |
| 116 | + | |
| 117 | + /* find the MP2 encoder */ | |
| 118 | + codec = avcodec_find_encoder(AV_CODEC_ID_MP2); | |
| 119 | + if (!codec) { | |
| 120 | + fprintf(stderr, "Codec not found\n"); | |
| 121 | + exit(1); | |
| 122 | + } | |
| 123 | + | |
| 124 | + c = avcodec_alloc_context3(codec); | |
| 125 | + if (!c) { | |
| 126 | + fprintf(stderr, "Could not allocate audio codec context\n"); | |
| 127 | + exit(1); | |
| 128 | + } | |
| 129 | + | |
| 130 | + /* put sample parameters */ | |
| 131 | + c->bit_rate = 64000; | |
| 132 | + | |
| 133 | + /* check that the encoder supports s16 pcm input */ | |
| 134 | + c->sample_fmt = AV_SAMPLE_FMT_S16; | |
| 135 | + if (!check_sample_fmt(codec, c->sample_fmt)) { | |
| 136 | + fprintf(stderr, "Encoder does not support sample format %s", | |
| 137 | + av_get_sample_fmt_name(c->sample_fmt)); | |
| 138 | + exit(1); | |
| 139 | + } | |
| 140 | + | |
| 141 | + /* select other audio parameters supported by the encoder */ | |
| 142 | + c->sample_rate = select_sample_rate(codec); | |
| 143 | + c->channel_layout = select_channel_layout(codec); | |
| 144 | + c->channels = av_get_channel_layout_nb_channels(c->channel_layout); | |
| 145 | + | |
| 146 | + /* open it */ | |
| 147 | + if (avcodec_open2(c, codec, NULL) < 0) { | |
| 148 | + fprintf(stderr, "Could not open codec\n"); | |
| 149 | + exit(1); | |
| 150 | + } | |
| 151 | + | |
| 152 | + f = fopen(filename, "wb"); | |
| 153 | + if (!f) { | |
| 154 | + fprintf(stderr, "Could not open %s\n", filename); | |
| 155 | + exit(1); | |
| 156 | + } | |
| 157 | + | |
| 158 | + /* frame containing input raw audio */ | |
| 159 | + frame = av_frame_alloc(); | |
| 160 | + if (!frame) { | |
| 161 | + fprintf(stderr, "Could not allocate audio frame\n"); | |
| 162 | + exit(1); | |
| 163 | + } | |
| 164 | + | |
| 165 | + frame->nb_samples = c->frame_size; | |
| 166 | + frame->format = c->sample_fmt; | |
| 167 | + frame->channel_layout = c->channel_layout; | |
| 168 | + | |
| 169 | + /* the codec gives us the frame size, in samples, | |
| 170 | + * we calculate the size of the samples buffer in bytes */ | |
| 171 | + buffer_size = av_samples_get_buffer_size(NULL, c->channels, c->frame_size, | |
| 172 | + c->sample_fmt, 0); | |
| 173 | + if (buffer_size < 0) { | |
| 174 | + fprintf(stderr, "Could not get sample buffer size\n"); | |
| 175 | + exit(1); | |
| 176 | + } | |
| 177 | + samples = av_malloc(buffer_size); | |
| 178 | + if (!samples) { | |
| 179 | + fprintf(stderr, "Could not allocate %d bytes for samples buffer\n", | |
| 180 | + buffer_size); | |
| 181 | + exit(1); | |
| 182 | + } | |
| 183 | + /* setup the data pointers in the AVFrame */ | |
| 184 | + ret = avcodec_fill_audio_frame(frame, c->channels, c->sample_fmt, | |
| 185 | + (const uint8_t*)samples, buffer_size, 0); | |
| 186 | + if (ret < 0) { | |
| 187 | + fprintf(stderr, "Could not setup audio frame\n"); | |
| 188 | + exit(1); | |
| 189 | + } | |
| 190 | + | |
| 191 | + /* encode a single tone sound */ | |
| 192 | + t = 0; | |
| 193 | + tincr = 2 * M_PI * 440.0 / c->sample_rate; | |
| 194 | + for (i = 0; i < 200; i++) { | |
| 195 | + av_init_packet(&pkt); | |
| 196 | + pkt.data = NULL; // packet data will be allocated by the encoder | |
| 197 | + pkt.size = 0; | |
| 198 | + | |
| 199 | + for (j = 0; j < c->frame_size; j++) { | |
| 200 | + samples[2*j] = (int)(sin(t) * 10000); | |
| 201 | + | |
| 202 | + for (k = 1; k < c->channels; k++) | |
| 203 | + samples[2*j + k] = samples[2*j]; | |
| 204 | + t += tincr; | |
| 205 | + } | |
| 206 | + /* encode the samples */ | |
| 207 | + ret = avcodec_encode_audio2(c, &pkt, frame, &got_output); | |
| 208 | + if (ret < 0) { | |
| 209 | + fprintf(stderr, "Error encoding audio frame\n"); | |
| 210 | + exit(1); | |
| 211 | + } | |
| 212 | + if (got_output) { | |
| 213 | + fwrite(pkt.data, 1, pkt.size, f); | |
| 214 | + av_free_packet(&pkt); | |
| 215 | + } | |
| 216 | + } | |
| 217 | + | |
| 218 | + /* get the delayed frames */ | |
| 219 | + for (got_output = 1; got_output; i++) { | |
| 220 | + ret = avcodec_encode_audio2(c, &pkt, NULL, &got_output); | |
| 221 | + if (ret < 0) { | |
| 222 | + fprintf(stderr, "Error encoding frame\n"); | |
| 223 | + exit(1); | |
| 224 | + } | |
| 225 | + | |
| 226 | + if (got_output) { | |
| 227 | + fwrite(pkt.data, 1, pkt.size, f); | |
| 228 | + av_free_packet(&pkt); | |
| 229 | + } | |
| 230 | + } | |
| 231 | + fclose(f); | |
| 232 | + | |
| 233 | + av_freep(&samples); | |
| 234 | + av_frame_free(&frame); | |
| 235 | + avcodec_close(c); | |
| 236 | + av_free(c); | |
| 237 | +} | |
| 238 | + | |
| 239 | +/* | |
| 240 | + * Audio decoding. | |
| 241 | + */ | |
| 242 | +static void audio_decode_example(const char *outfilename, const char *filename) | |
| 243 | +{ | |
| 244 | + AVCodec *codec; | |
| 245 | + AVCodecContext *c= NULL; | |
| 246 | + int len; | |
| 247 | + FILE *f, *outfile; | |
| 248 | + uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE]; | |
| 249 | + AVPacket avpkt; | |
| 250 | + AVFrame *decoded_frame = NULL; | |
| 251 | + | |
| 252 | + av_init_packet(&avpkt); | |
| 253 | + | |
| 254 | + printf("Decode audio file %s to %s\n", filename, outfilename); | |
| 255 | + | |
| 256 | + /* find the mpeg audio decoder */ | |
| 257 | + codec = avcodec_find_decoder(AV_CODEC_ID_MP2); | |
| 258 | + if (!codec) { | |
| 259 | + fprintf(stderr, "Codec not found\n"); | |
| 260 | + exit(1); | |
| 261 | + } | |
| 262 | + | |
| 263 | + c = avcodec_alloc_context3(codec); | |
| 264 | + if (!c) { | |
| 265 | + fprintf(stderr, "Could not allocate audio codec context\n"); | |
| 266 | + exit(1); | |
| 267 | + } | |
| 268 | + | |
| 269 | + /* open it */ | |
| 270 | + if (avcodec_open2(c, codec, NULL) < 0) { | |
| 271 | + fprintf(stderr, "Could not open codec\n"); | |
| 272 | + exit(1); | |
| 273 | + } | |
| 274 | + | |
| 275 | + f = fopen(filename, "rb"); | |
| 276 | + if (!f) { | |
| 277 | + fprintf(stderr, "Could not open %s\n", filename); | |
| 278 | + exit(1); | |
| 279 | + } | |
| 280 | + outfile = fopen(outfilename, "wb"); | |
| 281 | + if (!outfile) { | |
| 282 | + av_free(c); | |
| 283 | + exit(1); | |
| 284 | + } | |
| 285 | + | |
| 286 | + /* decode until eof */ | |
| 287 | + avpkt.data = inbuf; | |
| 288 | + avpkt.size = fread(inbuf, 1, AUDIO_INBUF_SIZE, f); | |
| 289 | + | |
| 290 | + while (avpkt.size > 0) { | |
| 291 | + int got_frame = 0; | |
| 292 | + | |
| 293 | + if (!decoded_frame) { | |
| 294 | + if (!(decoded_frame = av_frame_alloc())) { | |
| 295 | + fprintf(stderr, "Could not allocate audio frame\n"); | |
| 296 | + exit(1); | |
| 297 | + } | |
| 298 | + } | |
| 299 | + | |
| 300 | + len = avcodec_decode_audio4(c, decoded_frame, &got_frame, &avpkt); | |
| 301 | + if (len < 0) { | |
| 302 | + fprintf(stderr, "Error while decoding\n"); | |
| 303 | + exit(1); | |
| 304 | + } | |
| 305 | + if (got_frame) { | |
| 306 | + /* if a frame has been decoded, output it */ | |
| 307 | + int data_size = av_samples_get_buffer_size(NULL, c->channels, | |
| 308 | + decoded_frame->nb_samples, | |
| 309 | + c->sample_fmt, 1); | |
| 310 | + if (data_size < 0) { | |
| 311 | + /* This should not occur, checking just for paranoia */ | |
| 312 | + fprintf(stderr, "Failed to calculate data size\n"); | |
| 313 | + exit(1); | |
| 314 | + } | |
| 315 | + fwrite(decoded_frame->data[0], 1, data_size, outfile); | |
| 316 | + } | |
| 317 | + avpkt.size -= len; | |
| 318 | + avpkt.data += len; | |
| 319 | + avpkt.dts = | |
| 320 | + avpkt.pts = AV_NOPTS_VALUE; | |
| 321 | + if (avpkt.size < AUDIO_REFILL_THRESH) { | |
| 322 | + /* Refill the input buffer, to avoid trying to decode | |
| 323 | + * incomplete frames. Instead of this, one could also use | |
| 324 | + * a parser, or use a proper container format through | |
| 325 | + * libavformat. */ | |
| 326 | + memmove(inbuf, avpkt.data, avpkt.size); | |
| 327 | + avpkt.data = inbuf; | |
| 328 | + len = fread(avpkt.data + avpkt.size, 1, | |
| 329 | + AUDIO_INBUF_SIZE - avpkt.size, f); | |
| 330 | + if (len > 0) | |
| 331 | + avpkt.size += len; | |
| 332 | + } | |
| 333 | + } | |
| 334 | + | |
| 335 | + fclose(outfile); | |
| 336 | + fclose(f); | |
| 337 | + | |
| 338 | + avcodec_close(c); | |
| 339 | + av_free(c); | |
| 340 | + av_frame_free(&decoded_frame); | |
| 341 | +} | |
| 342 | + | |
| 343 | +/* | |
| 344 | + * Video encoding example | |
| 345 | + */ | |
| 346 | +static void video_encode_example(const char *filename, int codec_id) | |
| 347 | +{ | |
| 348 | + AVCodec *codec; | |
| 349 | + AVCodecContext *c= NULL; | |
| 350 | + int i, ret, x, y, got_output; | |
| 351 | + FILE *f; | |
| 352 | + AVFrame *frame; | |
| 353 | + AVPacket pkt; | |
| 354 | + uint8_t endcode[] = { 0, 0, 1, 0xb7 }; | |
| 355 | + | |
| 356 | + printf("Encode video file %s\n", filename); | |
| 357 | + | |
| 358 | + /* find the mpeg1 video encoder */ | |
| 359 | + codec = avcodec_find_encoder(codec_id); | |
| 360 | + if (!codec) { | |
| 361 | + fprintf(stderr, "Codec not found\n"); | |
| 362 | + exit(1); | |
| 363 | + } | |
| 364 | + | |
| 365 | + c = avcodec_alloc_context3(codec); | |
| 366 | + if (!c) { | |
| 367 | + fprintf(stderr, "Could not allocate video codec context\n"); | |
| 368 | + exit(1); | |
| 369 | + } | |
| 370 | + | |
| 371 | + /* put sample parameters */ | |
| 372 | + c->bit_rate = 400000; | |
| 373 | + /* resolution must be a multiple of two */ | |
| 374 | + c->width = 352; | |
| 375 | + c->height = 288; | |
| 376 | + /* frames per second */ | |
| 377 | + c->time_base = (AVRational){1,25}; | |
| 378 | + /* emit one intra frame every ten frames | |
| 379 | + * check frame pict_type before passing frame | |
| 380 | + * to encoder, if frame->pict_type is AV_PICTURE_TYPE_I | |
| 381 | + * then gop_size is ignored and the output of encoder | |
| 382 | + * will always be I frame irrespective to gop_size | |
| 383 | + */ | |
| 384 | + c->gop_size = 10; | |
| 385 | + c->max_b_frames = 1; | |
| 386 | + c->pix_fmt = AV_PIX_FMT_YUV420P; | |
| 387 | + | |
| 388 | + if (codec_id == AV_CODEC_ID_H264) | |
| 389 | + av_opt_set(c->priv_data, "preset", "slow", 0); | |
| 390 | + | |
| 391 | + /* open it */ | |
| 392 | + if (avcodec_open2(c, codec, NULL) < 0) { | |
| 393 | + fprintf(stderr, "Could not open codec\n"); | |
| 394 | + exit(1); | |
| 395 | + } | |
| 396 | + | |
| 397 | + f = fopen(filename, "wb"); | |
| 398 | + if (!f) { | |
| 399 | + fprintf(stderr, "Could not open %s\n", filename); | |
| 400 | + exit(1); | |
| 401 | + } | |
| 402 | + | |
| 403 | + frame = av_frame_alloc(); | |
| 404 | + if (!frame) { | |
| 405 | + fprintf(stderr, "Could not allocate video frame\n"); | |
| 406 | + exit(1); | |
| 407 | + } | |
| 408 | + frame->format = c->pix_fmt; | |
| 409 | + frame->width = c->width; | |
| 410 | + frame->height = c->height; | |
| 411 | + | |
| 412 | + /* the image can be allocated by any means and av_image_alloc() is | |
| 413 | + * just the most convenient way if av_malloc() is to be used */ | |
| 414 | + ret = av_image_alloc(frame->data, frame->linesize, c->width, c->height, | |
| 415 | + c->pix_fmt, 32); | |
| 416 | + if (ret < 0) { | |
| 417 | + fprintf(stderr, "Could not allocate raw picture buffer\n"); | |
| 418 | + exit(1); | |
| 419 | + } | |
| 420 | + | |
| 421 | + /* encode 1 second of video */ | |
| 422 | + for (i = 0; i < 25; i++) { | |
| 423 | + av_init_packet(&pkt); | |
| 424 | + pkt.data = NULL; // packet data will be allocated by the encoder | |
| 425 | + pkt.size = 0; | |
| 426 | + | |
| 427 | + fflush(stdout); | |
| 428 | + /* prepare a dummy image */ | |
| 429 | + /* Y */ | |
| 430 | + for (y = 0; y < c->height; y++) { | |
| 431 | + for (x = 0; x < c->width; x++) { | |
| 432 | + frame->data[0][y * frame->linesize[0] + x] = x + y + i * 3; | |
| 433 | + } | |
| 434 | + } | |
| 435 | + | |
| 436 | + /* Cb and Cr */ | |
| 437 | + for (y = 0; y < c->height/2; y++) { | |
| 438 | + for (x = 0; x < c->width/2; x++) { | |
| 439 | + frame->data[1][y * frame->linesize[1] + x] = 128 + y + i * 2; | |
| 440 | + frame->data[2][y * frame->linesize[2] + x] = 64 + x + i * 5; | |
| 441 | + } | |
| 442 | + } | |
| 443 | + | |
| 444 | + frame->pts = i; | |
| 445 | + | |
| 446 | + /* encode the image */ | |
| 447 | + ret = avcodec_encode_video2(c, &pkt, frame, &got_output); | |
| 448 | + if (ret < 0) { | |
| 449 | + fprintf(stderr, "Error encoding frame\n"); | |
| 450 | + exit(1); | |
| 451 | + } | |
| 452 | + | |
| 453 | + if (got_output) { | |
| 454 | + printf("Write frame %3d (size=%5d)\n", i, pkt.size); | |
| 455 | + fwrite(pkt.data, 1, pkt.size, f); | |
| 456 | + av_free_packet(&pkt); | |
| 457 | + } | |
| 458 | + } | |
| 459 | + | |
| 460 | + /* get the delayed frames */ | |
| 461 | + for (got_output = 1; got_output; i++) { | |
| 462 | + fflush(stdout); | |
| 463 | + | |
| 464 | + ret = avcodec_encode_video2(c, &pkt, NULL, &got_output); | |
| 465 | + if (ret < 0) { | |
| 466 | + fprintf(stderr, "Error encoding frame\n"); | |
| 467 | + exit(1); | |
| 468 | + } | |
| 469 | + | |
| 470 | + if (got_output) { | |
| 471 | + printf("Write frame %3d (size=%5d)\n", i, pkt.size); | |
| 472 | + fwrite(pkt.data, 1, pkt.size, f); | |
| 473 | + av_free_packet(&pkt); | |
| 474 | + } | |
| 475 | + } | |
| 476 | + | |
| 477 | + /* add sequence end code to have a real mpeg file */ | |
| 478 | + fwrite(endcode, 1, sizeof(endcode), f); | |
| 479 | + fclose(f); | |
| 480 | + | |
| 481 | + avcodec_close(c); | |
| 482 | + av_free(c); | |
| 483 | + av_freep(&frame->data[0]); | |
| 484 | + av_frame_free(&frame); | |
| 485 | + printf("\n"); | |
| 486 | +} | |
| 487 | + | |
| 488 | +/* | |
| 489 | + * Video decoding example | |
| 490 | + */ | |
| 491 | + | |
| 492 | +static void pgm_save(unsigned char *buf, int wrap, int xsize, int ysize, | |
| 493 | + char *filename) | |
| 494 | +{ | |
| 495 | + FILE *f; | |
| 496 | + int i; | |
| 497 | + | |
| 498 | + f = fopen(filename,"w"); | |
| 499 | + fprintf(f, "P5\n%d %d\n%d\n", xsize, ysize, 255); | |
| 500 | + for (i = 0; i < ysize; i++) | |
| 501 | + fwrite(buf + i * wrap, 1, xsize, f); | |
| 502 | + fclose(f); | |
| 503 | +} | |
| 504 | + | |
| 505 | +static int decode_write_frame(const char *outfilename, AVCodecContext *avctx, | |
| 506 | + AVFrame *frame, int *frame_count, AVPacket *pkt, int last) | |
| 507 | +{ | |
| 508 | + int len, got_frame; | |
| 509 | + char buf[1024]; | |
| 510 | + | |
| 511 | + len = avcodec_decode_video2(avctx, frame, &got_frame, pkt); | |
| 512 | + if (len < 0) { | |
| 513 | + fprintf(stderr, "Error while decoding frame %d\n", *frame_count); | |
| 514 | + return len; | |
| 515 | + } | |
| 516 | + if (got_frame) { | |
| 517 | + printf("Saving %sframe %3d\n", last ? "last " : "", *frame_count); | |
| 518 | + fflush(stdout); | |
| 519 | + | |
| 520 | + /* the picture is allocated by the decoder, no need to free it */ | |
| 521 | + snprintf(buf, sizeof(buf), outfilename, *frame_count); | |
| 522 | + pgm_save(frame->data[0], frame->linesize[0], | |
| 523 | + avctx->width, avctx->height, buf); | |
| 524 | + (*frame_count)++; | |
| 525 | + } | |
| 526 | + if (pkt->data) { | |
| 527 | + pkt->size -= len; | |
| 528 | + pkt->data += len; | |
| 529 | + } | |
| 530 | + return 0; | |
| 531 | +} | |
| 532 | + | |
| 533 | +static void video_decode_example(const char *outfilename, const char *filename) | |
| 534 | +{ | |
| 535 | + AVCodec *codec; | |
| 536 | + AVCodecContext *c= NULL; | |
| 537 | + int frame_count; | |
| 538 | + FILE *f; | |
| 539 | + AVFrame *frame; | |
| 540 | + uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE]; | |
| 541 | + AVPacket avpkt; | |
| 542 | + | |
| 543 | + av_init_packet(&avpkt); | |
| 544 | + | |
| 545 | + /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */ | |
| 546 | + memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE); | |
| 547 | + | |
| 548 | + printf("Decode video file %s to %s\n", filename, outfilename); | |
| 549 | + | |
| 550 | + /* find the mpeg1 video decoder */ | |
| 551 | + codec = avcodec_find_decoder(AV_CODEC_ID_MPEG1VIDEO); | |
| 552 | + if (!codec) { | |
| 553 | + fprintf(stderr, "Codec not found\n"); | |
| 554 | + exit(1); | |
| 555 | + } | |
| 556 | + | |
| 557 | + c = avcodec_alloc_context3(codec); | |
| 558 | + if (!c) { | |
| 559 | + fprintf(stderr, "Could not allocate video codec context\n"); | |
| 560 | + exit(1); | |
| 561 | + } | |
| 562 | + | |
| 563 | + if(codec->capabilities&CODEC_CAP_TRUNCATED) | |
| 564 | + c->flags|= CODEC_FLAG_TRUNCATED; /* we do not send complete frames */ | |
| 565 | + | |
| 566 | + /* For some codecs, such as msmpeg4 and mpeg4, width and height | |
| 567 | + MUST be initialized there because this information is not | |
| 568 | + available in the bitstream. */ | |
| 569 | + | |
| 570 | + /* open it */ | |
| 571 | + if (avcodec_open2(c, codec, NULL) < 0) { | |
| 572 | + fprintf(stderr, "Could not open codec\n"); | |
| 573 | + exit(1); | |
| 574 | + } | |
| 575 | + | |
| 576 | + f = fopen(filename, "rb"); | |
| 577 | + if (!f) { | |
| 578 | + fprintf(stderr, "Could not open %s\n", filename); | |
| 579 | + exit(1); | |
| 580 | + } | |
| 581 | + | |
| 582 | + frame = av_frame_alloc(); | |
| 583 | + if (!frame) { | |
| 584 | + fprintf(stderr, "Could not allocate video frame\n"); | |
| 585 | + exit(1); | |
| 586 | + } | |
| 587 | + | |
| 588 | + frame_count = 0; | |
| 589 | + for (;;) { | |
| 590 | + avpkt.size = fread(inbuf, 1, INBUF_SIZE, f); | |
| 591 | + if (avpkt.size == 0) | |
| 592 | + break; | |
| 593 | + | |
| 594 | + /* NOTE1: some codecs are stream based (mpegvideo, mpegaudio) | |
| 595 | + and this is the only method to use them because you cannot | |
| 596 | + know the compressed data size before analysing it. | |
| 597 | + | |
| 598 | + BUT some other codecs (msmpeg4, mpeg4) are inherently frame | |
| 599 | + based, so you must call them with all the data for one | |
| 600 | + frame exactly. You must also initialize 'width' and | |
| 601 | + 'height' before initializing them. */ | |
| 602 | + | |
| 603 | + /* NOTE2: some codecs allow the raw parameters (frame size, | |
| 604 | + sample rate) to be changed at any frame. We handle this, so | |
| 605 | + you should also take care of it */ | |
| 606 | + | |
| 607 | + /* here, we use a stream based decoder (mpeg1video), so we | |
| 608 | + feed decoder and see if it could decode a frame */ | |
| 609 | + avpkt.data = inbuf; | |
| 610 | + while (avpkt.size > 0) | |
| 611 | + if (decode_write_frame(outfilename, c, frame, &frame_count, &avpkt, 0) < 0) | |
| 612 | + exit(1); | |
| 613 | + } | |
| 614 | + | |
| 615 | + /* some codecs, such as MPEG, transmit the I and P frame with a | |
| 616 | + latency of one frame. You must do the following to have a | |
| 617 | + chance to get the last frame of the video */ | |
| 618 | + avpkt.data = NULL; | |
| 619 | + avpkt.size = 0; | |
| 620 | + decode_write_frame(outfilename, c, frame, &frame_count, &avpkt, 1); | |
| 621 | + | |
| 622 | + fclose(f); | |
| 623 | + | |
| 624 | + avcodec_close(c); | |
| 625 | + av_free(c); | |
| 626 | + av_frame_free(&frame); | |
| 627 | + printf("\n"); | |
| 628 | +} | |
| 629 | + | |
| 630 | +int main(int argc, char **argv) | |
| 631 | +{ | |
| 632 | + const char *output_type; | |
| 633 | + | |
| 634 | + /* register all the codecs */ | |
| 635 | + avcodec_register_all(); | |
| 636 | + | |
| 637 | + if (argc < 2) { | |
| 638 | + printf("usage: %s output_type\n" | |
| 639 | + "API example program to decode/encode a media stream with libavcodec.\n" | |
| 640 | + "This program generates a synthetic stream and encodes it to a file\n" | |
| 641 | + "named test.h264, test.mp2 or test.mpg depending on output_type.\n" | |
| 642 | + "The encoded stream is then decoded and written to a raw data output.\n" | |
| 643 | + "output_type must be choosen between 'h264', 'mp2', 'mpg'.\n", | |
| 644 | + argv[0]); | |
| 645 | + return 1; | |
| 646 | + } | |
| 647 | + output_type = argv[1]; | |
| 648 | + | |
| 649 | + if (!strcmp(output_type, "h264")) { | |
| 650 | + video_encode_example("test.h264", AV_CODEC_ID_H264); | |
| 651 | + } else if (!strcmp(output_type, "mp2")) { | |
| 652 | + audio_encode_example("test.mp2"); | |
| 653 | + audio_decode_example("test.sw", "test.mp2"); | |
| 654 | + } else if (!strcmp(output_type, "mpg")) { | |
| 655 | + video_encode_example("test.mpg", AV_CODEC_ID_MPEG1VIDEO); | |
| 656 | + video_decode_example("test%02d.pgm", "test.mpg"); | |
| 657 | + } else { | |
| 658 | + fprintf(stderr, "Invalid output type '%s', choose between 'h264', 'mp2', or 'mpg'\n", | |
| 659 | + output_type); | |
| 660 | + return 1; | |
| 661 | + } | |
| 662 | + | |
| 663 | + return 0; | |
| 664 | +} | |