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• How to write NALs produced by x264_encoder_encode() using ffmpeg av_interleaved_write_frame()

  21 janvier 2013, par Haleeq Usman

  I have been trying to produce a "flv" video file in the following sequence :

  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.

  Here is the implementation for the add_stream() function :

  /* 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;
  
  }

  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 !

• How to write NALs produced by x264_encoder_encode() using ffmpeg av_interleaved_write_frame()

  21 janvier 2013, par Haleeq Usman

  I have been trying to produce a "flv" video file in the following sequence :

  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.

  Here is the implementation for the add_stream() function :

  /* 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;
  
  }

  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 !

• FFMPEG - Converting any kind of file to Mp4 compatible with IOS and Flash

  5 février 2013, par arashaga

  I am struggling with FFmpeg whithing Drupal Video Module to produce files to MP4 that is compatible with IOS and Flash Player10 and up.
  I have used the following commands so far, please note that the variables starting with " !" are placeholders and will be replaces with the proper items :

  FFmpeg -strict experimental -y -i !videofile -pass 1 -s !widthx!height -b:v 500k -threads 0 -vcodec libx264 -vf "pad=!paddingwidth:!paddingheight:!paddingleft:!paddingtop:000000" -preset slow -an !convertfile
  
  
  
  FFmpeg -strict experimental -y -i !videofile -pass 2 -s !widthx!height -b:v 500k -threads 0 -vcodec libx264 -vf "pad=!paddingwidth:!paddingheight:!paddingleft:!paddingtop:000000" -preset slow -acodec aac -ab 128k !convertfile

  The above command produce an error as :

  error executing command for rendering preset HTML5 MP4, command #1 :

  nice -n 19 /usr/bin/ffmpeg/ffmpeg -y -i '80137db8c3_1334836277_int_tr_19.mp4' -s 176x100 -b:v 500k -threads 0 -vcodec libx264 -preset slow -acodec aac -ab 128k '/converted/80137db8c3_1334836277_int_tr_19.mp4' 2>&1
  
  
  
  Output:
  
  
  
  ffmpeg version git-2013-02-01-5a67e30 Copyright (c) 2000-2013 the FFmpeg developers
  
    built on Feb  1 2013 14:23:14 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
  
    configuration: --enable-gpl --enable-libass --enable-libfaac --enable-libfdk-aac --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-librtmp --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-nonfree --enable-version3
  
    libavutil      52. 17.100 / 52. 17.100
  
    libavcodec     54. 91.100 / 54. 91.100
  
    libavformat    54. 61.104 / 54. 61.104
  
    libavdevice    54.  3.103 / 54.  3.103
  
    libavfilter     3. 35.100 /  3. 35.100
  
    libswscale      2.  2.100 /  2.  2.100
  
    libswresample   0. 17.102 /  0. 17.102
  
    libpostproc    52.  2.100 / 52.  2.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '80137db8c3_1334836277_int_tr_19.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: isommp42
  
      creation_time   : 2011-03-28 00:12:26
  
    Duration: 00:02:01.14, start: 0.000000, bitrate: 703 kb/s
  
      Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 601 kb/s, 29.96 fps, 29.92 tbr, 1k tbn, 59.83 tbc
  
      Metadata:
  
        creation_time   : 1970-01-01 00:00:00
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 96 kb/s
  
      Metadata:
  
        creation_time   : 2011-03-28 00:12:27
  
        handler_name    : (C) 2007 Google Inc. v08.13.2007.
  
  [libx264 @ 0x34ec060] using SAR=100/99
  
  [libx264 @ 0x34ec060] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2 AVX
  
  [libx264 @ 0x34ec060] profile High, level 2.0
  
  [libx264 @ 0x34ec060] 264 - core 129 r2245 bc13772 - H.264/MPEG-4 AVC codec - Copyleft 2003-2013 - http://www.videolan.org/x264.html - options: cabac=1 ref=5 deblock=1:0:0 analyse=0x3:0x113 me=umh subme=8 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=2 b_bias=0 direct=3 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=50 rc=abr mbtree=1 bitrate=500 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
  
  The encoder 'aac' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it.
  
  Alternatively use the non experimental encoder 'libfaac'.

  Another command that I used is :

  FFmpeg -i !videofile -an -pass 1 -vcodec libx264 -preset slow -b 500k -threads auto !convertfile
  
  
  
  FFMpeg -y -i !videofile -acodec libfaac -ab 128k -pass 2 -vcodec libx264 -preset slow -b 500k -threads auto !convertfile

  Output for the first pass :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'comiccon.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: mp41
  
      creation_time   : 2012-08-15 17:12:37
  
    Duration: 01:17:15.93, start: 0.000000, bitrate: 706 kb/s
  
      Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 636 kb/s, 30 fps, 30 tbr, 90k tbn, 60 tbc
  
      Metadata:
  
        creation_time   : 2012-08-15 17:12:37
  
        handler_name    : VideoHandler
  
      Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 63 kb/s
  
      Metadata:
  
        creation_time   : 2012-08-15 17:12:37
  
        handler_name    : SoundHandler
  
  Please use -b:a or -b:v, -b is ambiguous
  
  
  
  using SAR=1/1
  
  [libx264 @ 0x1c39be0] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2 AVX
  
  [libx264 @ 0x1c39be0] profile Main, level 3.0
  
  [libx264 @ 0x1c39be0] 264 - core 129 r2245 bc13772 - H.264/MPEG-4 AVC codec - Copyleft 2003-2013 - http://www.videolan.org/x264.html - options: cabac=1 ref=1 deblock=1:0:0 analyse=0x1:0 me=dia subme=2 psy=1 psy_rd=1.00:0.00 mixed_ref=0 me_range=16 chroma_me=1 trellis=0 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=0 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=2 b_bias=0 direct=3 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=50 rc=abr mbtree=1 bitrate=500 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
  
  Output #0, mp4, to 'comiccon.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: mp41
  
      encoder         : Lavf54.61.104
  
      Stream #0:0(eng): Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 640x360 [SAR 1:1 DAR 16:9], q=-1--1, pass 1, 500 kb/s, 15360 tbn, 30 tbc
  
      Metadata:
  
        creation_time   : 2012-08-15 17:12:37
  
        handler_name    : VideoHandler
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 -> libx264)
  
  Press [q] to stop, [?] for help
  
  frame=139078 fps=279 q=32766.0 Lsize=  286145kB time=01:17:15.86 bitrate= 505.6kbits/s    
  
  video:284758kB audio:0kB subtitle:0 global headers:0kB muxing overhead 0.487000%
  
  [libx264 @ 0x1c39be0] frame I:656   Avg QP:19.51  size: 21457
  
  [libx264 @ 0x1c39be0] frame P:76006 Avg QP:22.19  size:  3141
  
  [libx264 @ 0x1c39be0] frame B:62416 Avg QP:26.38  size:   621
  
  [libx264 @ 0x1c39be0] consecutive B-frames: 32.3% 17.5% 18.6% 31.6%
  
  [libx264 @ 0x1c39be0] mb I  I16..4: 24.5%  0.0% 75.5%
  
  [libx264 @ 0x1c39be0] mb P  I16..4:  7.5%  0.0%  0.0%  P16..4: 40.5%  0.0%  0.0%  0.0%  0.0%    skip:52.1%
  
  [libx264 @ 0x1c39be0] mb B  I16..4:  1.4%  0.0%  0.0%  B16..8: 12.0%  0.0%  0.0%  direct: 2.9%  skip:83.7%  L0:41.1% L1:41.6% BI:17.3%
  
  [libx264 @ 0x1c39be0] final ratefactor: 23.45
  
  [libx264 @ 0x1c39be0] direct mvs  spatial:95.3% temporal:4.7%
  
  [libx264 @ 0x1c39be0] coded y,uvDC,uvAC intra: 37.6% 42.8% 11.8% inter: 8.9% 8.2% 0.5%
  
  [libx264 @ 0x1c39be0] i16 v,h,dc,p: 43% 28% 19% 10%
  
  [libx264 @ 0x1c39be0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 36% 21% 11%  6%  4%  5%  4%  6%  6%
  
  [libx264 @ 0x1c39be0] i8c dc,h,v,p: 57% 19% 20%  4%
  
  [libx264 @ 0x1c39be0] Weighted P-Frames: Y:1.4% UV:0.5%
  
  [libx264 @ 0x1c39be0] kb/s:503.18

  output for the second pass :

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'comiccon.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: mp41
  
      creation_time   : 2012-08-15 17:12:37
  
    Duration: 01:17:15.93, start: 0.000000, bitrate: 706 kb/s
  
      Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 636 kb/s, 30 fps, 30 tbr, 90k tbn, 60 tbc
  
      Metadata:
  
        creation_time   : 2012-08-15 17:12:37
  
        handler_name    : VideoHandler
  
      Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 63 kb/s
  
      Metadata:
  
        creation_time   : 2012-08-15 17:12:37
  
        handler_name    : SoundHandler
  
  Please use -b:a or -b:v, -b is ambiguous
  
  [libx264 @ 0x3247f80] using SAR=1/1
  
  [libx264 @ 0x3247f80] using cpu capabilities: MMX2 SSE2Fast SSSE3 FastShuffle SSE4.2 AVX
  
  [libx264 @ 0x3247f80] profile High, level 3.0
  
  [libx264 @ 0x3247f80] 264 - core 129 r2245 bc13772 - H.264/MPEG-4 AVC codec - Copyleft 2003-2013 - http://www.videolan.org/x264.html - options: cabac=1 ref=5 deblock=1:0:0 analyse=0x3:0x113 me=umh subme=8 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=2 b_bias=0 direct=3 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=50 rc=2pass mbtree=1 bitrate=500 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 cplxblur=20.0 qblur=0.5 ip_ratio=1.40 aq=1:1.00
  
  Output #0, mp4, to 'comiccon.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: mp41
  
      encoder         : Lavf54.61.104
  
      Stream #0:0(eng): Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 640x360 [SAR 1:1 DAR 16:9], q=-1--1, pass 2, 500 kb/s, 15360 tbn, 30 tbc
  
      Metadata:
  
        creation_time   : 2012-08-15 17:12:37
  
        handler_name    : VideoHandler
  
      Stream #0:1(eng): Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, stereo, s16, 128 kb/s
  
      Metadata:
  
        creation_time   : 2012-08-15 17:12:37
  
        handler_name    : SoundHandler
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 -> libx264)
  
    Stream #0:1 -> #0:1 (aac -> libfaac)
  
  Press [q] to stop, [?] for help
  
  frame=139078 fps=206 q=32766.0 Lsize=  357252kB time=01:17:15.93 bitrate= 631.3kbits/s    
  
  video:282992kB audio:69592kB subtitle:0 global headers:0kB muxing overhead 1.324238%
  
  [libx264 @ 0x3247f80] frame I:656   Avg QP:19.61  size: 20433
  
  [libx264 @ 0x3247f80] frame P:76006 Avg QP:23.07  size:  2996
  
  [libx264 @ 0x3247f80] frame B:62416 Avg QP:26.23  size:   780
  
  [libx264 @ 0x3247f80] consecutive B-frames: 32.3% 17.5% 18.6% 31.6%
  
  [libx264 @ 0x3247f80] mb I  I16..4: 17.2% 37.8% 44.9%
  
  [libx264 @ 0x3247f80] mb P  I16..4:  2.9%  3.7%  1.2%  P16..4: 30.3%  6.1%  3.4%  0.0%  0.0%    skip:52.5%
  
  [libx264 @ 0x3247f80] mb B  I16..4:  0.5%  0.6%  0.3%  B16..8: 25.9%  2.2%  0.5%  direct: 0.9%  skip:69.3%  L0:51.4% L1:43.0% BI: 5.7%
  
  [libx264 @ 0x3247f80] 8x8 transform intra:45.9% inter:51.5%
  
  [libx264 @ 0x3247f80] direct mvs  spatial:85.5% temporal:14.5%
  
  [libx264 @ 0x3247f80] coded y,uvDC,uvAC intra: 47.3% 49.2% 13.5% inter: 9.0% 9.4% 0.5%
  
  [libx264 @ 0x3247f80] i16 v,h,dc,p: 38% 27% 13% 22%
  
  [libx264 @ 0x3247f80] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 29% 16% 14%  5%  5%  7%  7%  8%  9%
  
  [libx264 @ 0x3247f80] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 31% 15%  9%  6%  7%  8%  7%  8%  8%
  
  [libx264 @ 0x3247f80] i8c dc,h,v,p: 49% 22% 20%  8%
  
  [libx264 @ 0x3247f80] Weighted P-Frames: Y:1.4% UV:0.5%
  
  [libx264 @ 0x3247f80] ref P L0: 79.3% 10.4%  6.8%  1.6%  1.2%  0.7%  0.0%
  
  [libx264 @ 0x3247f80] ref B L0: 93.6%  4.8%  1.2%  0.3%
  
  [libx264 @ 0x3247f80] ref B L1: 96.6%  3.4%
  
  [libx264 @ 0x3247f80] kb/s:500.06

  The above command produces the file correctly however it cannot be played in flash player. One thing that I noticed is this may happen if the input file is mp4 as well. This command is executed for users uploading files, so the input file could be any format.

  Below is the information about my FFmpeg version :

  ffmpeg version git-2013-02-01-5a67e30 Copyright (c) 2000-2013 the
  FFmpeg developers built on Feb 1 2013 14:23:14 with gcc 4.6
  (Ubuntu/Linaro 4.6.3-1ubuntu5) configuration : —enable-gpl
  —enable-libass —enable-libfaac —enable-libfdk-aac —enable-libmp3lame —enable-libopencore-amrnb —enable-libopencore-amrwb —enable-librtmp —enable-libtheora —enable-libvorbis —enable-libvpx —enable-libx264 —enable-nonfree —enable-version3 libavutil 52. 17.100 / 52. 17.100
  libavcodec 54. 91.100 / 54. 91.100
  libavformat 54. 61.104 / 54. 61.104
  libavdevice 54. 3.103 / 54. 3.103
  libavfilter 3. 35.100 / 3. 35.100
  libswscale 2. 2.100 / 2. 2.100
  libswresample 0. 17.102 / 0. 17.102
  libpostproc 52. 2.100 / 52. 2.1

  Thanks,