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POHow to write NALs produced by x264_encoder_encode() using ffmpeg av_interleaved_write_frame()
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I have been trying to produce a "flv" video file in the following sequence: <pre><code>av_register_all(); // Open video file if (avformat_open_input(&pFormatCtx, "6.mp4", NULL, NULL) != 0) return -1; // Couldn't open file // Retrieve stream information if (avformat_find_stream_info(pFormatCtx, NULL) < 0) return -1; // Couldn't find stream information // Dump information about file onto standard error av_dump_format(pFormatCtx, 0, "input_file.mp4", 0); // Find the first video stream videoStream = -1; for (i = 0; i < pFormatCtx->nb_streams; i++) if (pFormatCtx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO) { videoStream = i; break; } if (videoStream == -1) return -1; // Didn't find a video stream // Get a pointer to the codec context for the video stream pCodecCtx = pFormatCtx->streams[videoStream]->codec; // Find the decoder for the video stream pCodec = avcodec_find_decoder(pCodecCtx->codec_id); if (pCodec == NULL) { fprintf(stderr, "Unsupported codec!\n"); return -1; // Codec not found } // Open codec if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0) return -1; // Could not open codec // Allocate video frame pFrame = avcodec_alloc_frame(); // Allocate video frame pFrame = avcodec_alloc_frame(); // Allocate an AVFrame structure pFrameYUV420 = avcodec_alloc_frame(); if (pFrameYUV420 == NULL) return -1; // Determine required buffer size and allocate buffer numBytes = avpicture_get_size(pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height); buffer = (uint8_t *) av_malloc(numBytes * sizeof(uint8_t)); // Assign appropriate parts of buffer to image planes in pFrameYUV420 // Note that pFrameYUV420 is an AVFrame, but AVFrame is a superset of AVPicture avpicture_fill((AVPicture *) pFrameRGB, buffer, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height); // Setup scaler img_convert_ctx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, SWS_BILINEAR, 0, 0, 0); if (img_convert_ctx == NULL) { fprintf(stderr, "Cannot initialize the conversion context!\n"); exit(1); } // Setup encoder/muxing now filename = "output_file.flv"; fmt = av_guess_format("flv", filename, NULL); if (fmt == NULL) { printf("Could not guess format.\n"); return -1; } /* allocate the output media context */ oc = avformat_alloc_context(); if (oc == NULL) { printf("could not allocate context.\n"); return -1; } oc->oformat = fmt; snprintf(oc->filename, sizeof(oc->filename), "%s", filename); video_st = NULL; if (fmt->video_codec != AV_CODEC_ID_NONE) { video_st = add_stream(oc, &video_codec, fmt->video_codec); } // Let's see some information about our format av_dump_format(oc, 0, filename, 1); /* open the output file, if needed */ if (!(fmt->flags & AVFMT_NOFILE)) { ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE); if (ret < 0) { fprintf(stderr, "Could not open '%s': %s\n", filename, av_err2str(ret)); return 1; } } /* Write the stream header, if any. */ ret = avformat_write_header(oc, NULL); if (ret < 0) { fprintf(stderr, "Error occurred when opening output file: %s\n", av_err2str(ret)); return 1; } // Setup x264 params x264_param_t param; x264_param_default_preset(&param, "veryfast", "zerolatency"); param.i_threads = 1; param.i_width = video_st->codec->width; param.i_height = video_st->codec->height; param.i_fps_num = STREAM_FRAME_RATE; // 30 fps, same as video param.i_fps_den = 1; // Intra refres: param.i_keyint_max = STREAM_FRAME_RATE; param.b_intra_refresh = 1; // Rate control: param.rc.i_rc_method = X264_RC_CRF; param.rc.f_rf_constant = 25; param.rc.f_rf_constant_max = 35; // For streaming: param.b_repeat_headers = 1; param.b_annexb = 1; x264_param_apply_profile(&param, "baseline"); x264_t* encoder = x264_encoder_open(&param); x264_picture_t pic_in, pic_out; x264_picture_alloc(&pic_in, X264_CSP_I420, video_st->codec->width, video_st->codec->height); x264_nal_t* nals; int i_nals; // The loop: // 1. Read frames // 2. Decode the frame // 3. Attempt to re-encode using x264 // 4. Write the x264 encoded frame using av_interleaved_write_frame while (av_read_frame(pFormatCtx, &packet) >= 0) { // Is this a packet from the video stream? if (packet.stream_index == videoStream) { // Decode video frame avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet); // Did we get a video frame? if (frameFinished) { sws_scale(img_convert_ctx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pic_in.img.plane, pic_in.img.i_stride); int frame_size = x264_encoder_encode(encoder, &nals, &i_nals, &pic_in, &pic_out); if (frame_size >= 0) { if (i_nals < 0) printf("invalid frame size: %d\n", i_nals); // write out NALs for (i = 0; i < i_nals; i++) { // initalize a packet AVPacket p; av_init_packet(&p); p.data = nals[i].p_payload; p.size = nals[i].i_payload; p.stream_index = video_st->index; p.flags = AV_PKT_FLAG_KEY; p.pts = AV_NOPTS_VALUE; p.dts = AV_NOPTS_VALUE; ret = av_interleaved_write_frame(oc, &p); } } printf("encoded frame #%d\n", frame_count); frame_count++; } } // Free the packet that was allocated by av_read_frame av_free_packet(&packet); } // Now we free up resources used/close codecs, and finally close our program. </code></pre> Here is the implementation for the add_stream() function: <pre><code>/* Add an output stream. */ static AVStream *add_stream(AVFormatContext *oc, AVCodec **codec, enum AVCodecID codec_id) { AVCodecContext *c; AVStream *st; int r; /* find the encoder */ *codec = avcodec_find_encoder(codec_id); if (!(*codec)) { fprintf(stderr, "Could not find encoder for '%s'\n", avcodec_get_name(codec_id)); exit(1); } st = avformat_new_stream(oc, *codec); if (!st) { fprintf(stderr, "Could not allocate stream\n"); exit(1); } st->id = oc->nb_streams - 1; c = st->codec; switch ((*codec)->type) { case AVMEDIA_TYPE_AUDIO: st->id = 1; c->sample_fmt = AV_SAMPLE_FMT_FLTP; c->bit_rate = 64000; c->sample_rate = 44100; c->channels = 2; break; case AVMEDIA_TYPE_VIDEO: avcodec_get_context_defaults3(c, *codec); c->codec_id = codec_id; c->bit_rate = 500*1000; //c->rc_min_rate = 500*1000; //c->rc_max_rate = 500*1000; //c->rc_buffer_size = 500*1000; /* Resolution must be a multiple of two. */ c->width = 1280; c->height = 720; /* timebase: This is the fundamental unit of time (in seconds) in terms * of which frame timestamps are represented. For fixed-fps content, * timebase should be 1/framerate and timestamp increments should be * identical to 1. */ c->time_base.den = STREAM_FRAME_RATE; c->time_base.num = 1; c->gop_size = 12; /* emit one intra frame every twelve frames at most */ c->pix_fmt = STREAM_PIX_FMT; if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) { /* just for testing, we also add B frames */ c->max_b_frames = 2; } if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) { /* Needed to avoid using macroblocks in which some coeffs overflow. * This does not happen with normal video, it just happens here as * the motion of the chroma plane does not match the luma plane. */ c->mb_decision = 2; } break; default: break; } /* Some formats want stream headers to be separate. */ if (oc->oformat->flags & AVFMT_GLOBALHEADER) c->flags |= CODEC_FLAG_GLOBAL_HEADER; return st; } </code></pre> After the encoding is complete, I check the output file output_file.flv. I notice it's size is very large: 101MB and it does not play. If I use ffmpeg to decode/encode the input file, then I get an output file about 83MB in size (which is about the same size as the original .mp4 file used as input). Also, the 83MB output from just using ffmpeg C api, as opposed to using x264 for the encoding step, plays just fine. Does anyone know where I am going wrong? I have tried researching this for a few days now but with no luck :(. I feel that I am close to making it work, however, I just cannot figure out what I am doing wrong. Thank you!
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<api><ffmpeg><decode><encode><x264>
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How to write NALs produced by x264_encoder_encode() using ffmpeg av_interleaved_write_frame()
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