void video_encode_example(const char *filename) { AVCodec *codec; AVCodecContext *c= NULL; int i, out_size, size, x, y, outbuf_size; FILE *f; AVFrame *picture; uint8_t *outbuf, *picture_buf; printf("Video encoding\n"); /* find the mpeg1 video encoder */ codec = avcodec_find_encoder(CODEC_ID_MPEG1VIDEO); if (!codec) { fprintf(stderr, "codec not found\n"); exit(1); } c= avcodec_alloc_context(); picture= avcodec_alloc_frame(); /* put sample parameters */ c->bit_rate = 400000; /* resolution must be a multiple of two */ c->width = 352; c->height = 288; /* frames per second */ c->frame_rate = 25; c->frame_rate_base= 1; c->gop_size = 10; /* emit one intra frame every ten frames */ c->max_b_frames=1; /* open it */ if (avcodec_open(c, codec) < 0) { fprintf(stderr, "could not open codec\n"); exit(1); } /* the codec gives us the frame size, in samples */ f = fopen(filename, "w"); if (!f) { fprintf(stderr, "could not open %s\n", filename); exit(1); } /* alloc image and output buffer */ outbuf_size = 100000; outbuf = malloc(outbuf_size); size = c->width * c->height; picture_buf = malloc((size * 3) / 2); /* size for YUV 420 */ picture->data[0] = picture_buf; picture->data[1] = picture->data[0] + size; picture->data[2] = picture->data[1] + size / 4; picture->linesize[0] = c->width; picture->linesize[1] = c->width / 2; picture->linesize[2] = c->width / 2; /* encode 1 second of video */ for(i=0;i<25;i++) { fflush(stdout); /* prepare a dummy image */ /* Y */ for(y=0;y<c->height;y++) { for(x=0;x<c->width;x++) { picture->data[0][y * picture->linesize[0] + x] = x + y + i * 3; } } /* Cb and Cr */ for(y=0;y<c->height/2;y++) { for(x=0;x<c->width/2;x++) { picture->data[1][y * picture->linesize[1] + x] = 128 + y + i * 2; picture->data[2][y * picture->linesize[2] + x] = 64 + x + i * 5; } } /* encode the image */ out_size = avcodec_encode_video(c, outbuf, outbuf_size, picture); printf("encoding frame %3d (size=%5d)\n", i, out_size); fwrite(outbuf, 1, out_size, f); } /* get the delayed frames */ for(; out_size; i++) { fflush(stdout); out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL); printf("write frame %3d (size=%5d)\n", i, out_size); fwrite(outbuf, 1, out_size, f); } /* add sequence end code to have a real mpeg file */ outbuf[0] = 0x00; outbuf[1] = 0x00; outbuf[2] = 0x01; outbuf[3] = 0xb7; fwrite(outbuf, 1, 4, f); fclose(f); free(picture_buf); free(outbuf); avcodec_close(c); free(c); free(picture); printf("\n"); }