Cómo convertir RGB de YUV420p para el codificador ffmpeg?

Quiero hacer un archivo de video .avi a partir de imágenes de mapas de bits usando el código c ++. Escribí el siguiente código:

//Get RGB array data from bmp file uint8_t* rgb24Data = new uint8_t[3*imgWidth*imgHeight]; hBitmap = (HBITMAP) LoadImage( NULL, _T("myfile.bmp"), IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE); GetDIBits(hdc, hBitmap, 0, imgHeight, rgb24Data , (BITMAPINFO*)&bmi, DIB_RGB_COLORS); /* Allocate the encoded raw picture. */ AVPicture dst_picture; avpicture_alloc(&dst_picture, AV_PIX_FMT_YUV420P, imgWidth, imgHeight); /* Convert rgb24Data to YUV420p and stored into array dst_picture.data */ RGB24toYUV420P(imgWidth, imgHeight, rgb24Data, dst_picture.data); //How to implement this function? //code for encode frame dst_picture here 

Mi problema es cómo implementar la función RGB24toYUV420P() , esta función convertirá los datos RGB24 de la matriz rgb24Data en YUV420p y almacenará en la matriz dst_picture.data para el codificador ffmpeg?

    Puedes usar SwScale

    Algo como esto:

     #include  SwsContext * ctx = sws_getContext(imgWidth, imgHeight, AV_PIX_FMT_RGB24, imgWidth, imgHeight, AV_PIX_FMT_YUV420P, 0, 0, 0, 0); uint8_t * inData[1] = { rgb24Data }; // RGB24 have one plane int inLinesize[1] = { 3*imgWidth }; // RGB stride sws_scale(ctx, inData, inLinesize, 0, imgHeight, dst_picture.data, dst_picture.linesize) 

    Tenga en cuenta que debe crear una instancia del objeto SwsContext solo una vez, no para cada cuadro.

    Ejemplo ejecutable en FFmpeg 2.7.6

    Esta respuesta me puso en el camino correcto, pero:

    • la API ha cambiado ligeramente desde: SwsContext * debe ser struct SwsContext * lugar
    • Quería un ejemplo ejecutable mínimo para probarlo

    El ejemplo sintetiza y codifica algunos marcos coloridos generados por generate_rgb .

    ffmpeg_encoder_set_frame_yuv_from_rgb realiza la conversión de RGB24 a YUV.

    Vista previa de la salida generada .

     #include  #include  #include  #include  static AVCodecContext *c = NULL; static AVFrame *frame; static AVPacket pkt; static FILE *file; struct SwsContext *sws_context = NULL; static void ffmpeg_encoder_set_frame_yuv_from_rgb(uint8_t *rgb) { const int in_linesize[1] = { 3 * c->width }; sws_context = sws_getCachedContext(sws_context, c->width, c->height, AV_PIX_FMT_RGB24, c->width, c->height, AV_PIX_FMT_YUV420P, 0, 0, 0, 0); sws_scale(sws_context, (const uint8_t * const *)&rgb, in_linesize, 0, c->height, frame->data, frame->linesize); } uint8_t* generate_rgb(int width, int height, int pts, uint8_t *rgb) { int x, y, cur; rgb = realloc(rgb, 3 * sizeof(uint8_t) * height * width); for (y = 0; y < height; y++) { for (x = 0; x < width; x++) { cur = 3 * (y * width + x); rgb[cur + 0] = 0; rgb[cur + 1] = 0; rgb[cur + 2] = 0; if ((frame->pts / 25) % 2 == 0) { if (y < height / 2) { if (x < width / 2) { /* Black. */ } else { rgb[cur + 0] = 255; } } else { if (x < width / 2) { rgb[cur + 1] = 255; } else { rgb[cur + 2] = 255; } } } else { if (y < height / 2) { rgb[cur + 0] = 255; if (x < width / 2) { rgb[cur + 1] = 255; } else { rgb[cur + 2] = 255; } } else { if (x < width / 2) { rgb[cur + 1] = 255; rgb[cur + 2] = 255; } else { rgb[cur + 0] = 255; rgb[cur + 1] = 255; rgb[cur + 2] = 255; } } } } } return rgb; } /* Allocate resources and write header data to the output file. */ void ffmpeg_encoder_start(const char *filename, int codec_id, int fps, int width, int height) { AVCodec *codec; int ret; codec = avcodec_find_encoder(codec_id); if (!codec) { fprintf(stderr, "Codec not found\n"); exit(1); } c = avcodec_alloc_context3(codec); if (!c) { fprintf(stderr, "Could not allocate video codec context\n"); exit(1); } c->bit_rate = 400000; c->width = width; c->height = height; c->time_base.num = 1; c->time_base.den = fps; c->gop_size = 10; c->max_b_frames = 1; c->pix_fmt = AV_PIX_FMT_YUV420P; if (codec_id == AV_CODEC_ID_H264) av_opt_set(c->priv_data, "preset", "slow", 0); if (avcodec_open2(c, codec, NULL) < 0) { fprintf(stderr, "Could not open codec\n"); exit(1); } file = fopen(filename, "wb"); if (!file) { fprintf(stderr, "Could not open %s\n", filename); exit(1); } frame = av_frame_alloc(); if (!frame) { fprintf(stderr, "Could not allocate video frame\n"); exit(1); } frame->format = c->pix_fmt; frame->width = c->width; frame->height = c->height; ret = av_image_alloc(frame->data, frame->linesize, c->width, c->height, c->pix_fmt, 32); if (ret < 0) { fprintf(stderr, "Could not allocate raw picture buffer\n"); exit(1); } } /* Write trailing data to the output file and free resources allocated by ffmpeg_encoder_start. */ void ffmpeg_encoder_finish(void) { uint8_t endcode[] = { 0, 0, 1, 0xb7 }; int got_output, ret; do { fflush(stdout); ret = avcodec_encode_video2(c, &pkt, NULL, &got_output); if (ret < 0) { fprintf(stderr, "Error encoding frame\n"); exit(1); } if (got_output) { fwrite(pkt.data, 1, pkt.size, file); av_packet_unref(&pkt); } } while (got_output); fwrite(endcode, 1, sizeof(endcode), file); fclose(file); avcodec_close(c); av_free(c); av_freep(&frame->data[0]); av_frame_free(&frame); } /* Encode one frame from an RGB24 input and save it to the output file. Must be called after ffmpeg_encoder_start, and ffmpeg_encoder_finish must be called after the last call to this function. */ void ffmpeg_encoder_encode_frame(uint8_t *rgb) { int ret, got_output; ffmpeg_encoder_set_frame_yuv_from_rgb(rgb); av_init_packet(&pkt); pkt.data = NULL; pkt.size = 0; ret = avcodec_encode_video2(c, &pkt, frame, &got_output); if (ret < 0) { fprintf(stderr, "Error encoding frame\n"); exit(1); } if (got_output) { fwrite(pkt.data, 1, pkt.size, file); av_packet_unref(&pkt); } } /* Represents the main loop of an application which generates one frame per loop. */ static void encode_example(const char *filename, int codec_id) { int pts; int width = 320; int height = 240; uint8_t *rgb = NULL; ffmpeg_encoder_start(filename, codec_id, 25, width, height); for (pts = 0; pts < 100; pts++) { frame->pts = pts; rgb = generate_rgb(width, height, pts, rgb); ffmpeg_encoder_encode_frame(rgb); } ffmpeg_encoder_finish(); free(rgb); } int main(void) { avcodec_register_all(); encode_example("tmp.h264", AV_CODEC_ID_H264); encode_example("tmp.mpg", AV_CODEC_ID_MPEG1VIDEO); /* TODO: is this encoded correctly? Possible to view it without container? */ /*encode_example("tmp.vp8", AV_CODEC_ID_VP8);*/ return 0; } 

    Probado en Ubuntu 15.10. Código en GitHub .