Recherche avancée

Sur d’autres sites (8701)

• Trying to cancel execution and delete file using ffmpeg C API

  6 mars 2020, par Vuwox

  The code below is a class that handle the conversion of multiples images, through add_frame() method, into a GIF with encode(). It also use a filter to generate and apply the palette. The usage is like this :

  Code call example

  std::unique_ptr gif_obj = nullptr;
  
  try
  
  {
  
      gif_obj = std::make_unique({1000,1000}, 12, "C:/out.gif",
  
                "format=pix_fmts=rgb24,split [a][b];[a]palettegen[p];[b][p]paletteuse");
  
  
  
      // Example: a simple vector of images (usually process internally)
  
      for(auto img : image_vector)
  
           gif_obj->add_frame(img);
  
  
  
      // Once all frame were added, encode the final GIF with the filter applied.
  
      gif_obj->encode();
  
  }
  
  catch(const std::exception& e)
  
  {
  
      // An error occured! We must close FFMPEG properly and delete the created file.
  
      gif_obj->cancel();
  
  }

  I have the following issue. If the code for any reason throw an exception, I call ffmpeg->cancel() and it supposes to delete the GIF file on disk. But this is never working, I assume there is a lock on the file or something like that. So here are my question :

  What is the proper way to close/free ffmpeg object in order to remove the file afterward ?

  ---

  Full class code below

  Header

  // C++ Standard includes    
  
  #include <memory>
  
  #include <string>
  
  #include <vector>
  
  
  
  
  
  // 3rd Party incldues
  
  #ifdef __cplusplus
  
  extern "C" {
  
  #include "libavformat/avformat.h"
  
  #include "libavfilter/avfilter.h"
  
  #include "libavutil/opt.h"
  
  #include "libavfilter/buffersrc.h"
  
  #include "libavfilter/buffersink.h"
  
  #include "libswscale/swscale.h"
  
  #include "libavutil/imgutils.h"
  
  }
  
  #endif
  
  
  
  #define FFMPEG_MSG_LEN 2000
  
  
  
  namespace px
  
  {
  
      namespace GIF
  
      {
  
          class FFMPEG
  
          {
  
          public:
  
              FFMPEG(const px::Point2D<int>&amp; dim,
  
                     const int framerate,
  
                     const std::string&amp; filename,
  
                     const std::string&amp; filter_cmd);
  
  
  
              ~FFMPEG();
  
  
  
              void add_frame(pxImage * const img);
  
              void encode();
  
              void cancel();
  
  
  
          private:
  
  
  
              void init_filters();            // Init everything that needed to filter the input frame.
  
              void init_muxer();              // The muxer that creates the output file.
  
              void muxing_one_frame(AVFrame* frame);
  
              void release();
  
  
  
              int _ret = 0;                   // status code from FFMPEG.
  
              char _err_msg[FFMPEG_MSG_LEN];  // Error message buffer.
  
  
  
  
  
              int m_width = 0;                // The width that all futur images must have to be accepted.
  
              int m_height = 0;               // The height that all futur images must have to be accepted.
  
  
  
              int m_framerate = 0;            // GIF Framerate.
  
              std::string m_filename = "";    // The GIF filename (on cache?)
  
              std::string m_filter_desc = ""; // The FFMPEG filter to apply over the frames.
  
  
  
              bool as_frame = false;
  
  
  
              AVFrame* picture_rgb24 = nullptr;           // Temporary frame that will hold the pxImage in an RGB24 format (NOTE: TOP-LEFT origin)
  
  
  
              AVFormatContext* ofmt_ctx = nullptr;        // ouput format context associated to the 
  
              AVCodecContext* o_codec_ctx = nullptr;      // output codec for the GIF
  
  
  
              AVFilterGraph* filter_graph = nullptr;      // filter graph associate with the string we want to execute
  
              AVFilterContext* buffersrc_ctx = nullptr;   // The buffer that will store all the frames in one place for the palette generation.
  
              AVFilterContext* buffersink_ctx = nullptr;  // The buffer that will store the result afterward (once the palette are used).
  
  
  
              int64_t m_pts_increment = 0;
  
          };
  
      };
  
  };
  
  </int></vector></string></memory>

  ctor

  px::GIF::FFMPEG::FFMPEG(const px::Point2D<int>&amp; dim,
  
                          const int framerate,
  
                          const std::string&amp; filename,
  
                          const std::string&amp; filter_cmd) :
  
      m_width(dim.x()),
  
      m_height(dim.y()),
  
      m_framerate(framerate),
  
      m_filename(filename),
  
      m_filter_desc(filter_cmd)
  
  {
  
  #if !_DEBUG
  
      av_log_set_level(AV_LOG_QUIET); // Set the FFMPEG log to quiet to avoid too much logs.
  
  #endif
  
  
  
      // Allocate the temporary buffer that hold the ffmpeg image (pxImage to AVFrame conversion).
  
      picture_rgb24 = av_frame_alloc();
  
      picture_rgb24->pts = 0;
  
      picture_rgb24->data[0] = NULL;
  
      picture_rgb24->linesize[0] = -1;
  
      picture_rgb24->format = AV_PIX_FMT_RGB24;
  
      picture_rgb24->height = m_height;
  
      picture_rgb24->width = m_width; 
  
  
  
      if ((_ret = av_image_alloc(picture_rgb24->data, picture_rgb24->linesize, m_width, m_height, (AVPixelFormat)picture_rgb24->format, 24)) &lt; 0)
  
          throw px::GIF::Error("Failed to allocate the AVFrame for pxImage conversion with error: " +
  
                               std::string(av_make_error_string(_err_msg, FFMPEG_MSG_LEN, _ret)),
  
                               "GIF::FFMPEG CTOR");   
  
  
  
      //printf("allocated picture of size %d, linesize %d %d %d %d\n", _ret, picture_rgb24->linesize[0], picture_rgb24->linesize[1], picture_rgb24->linesize[2], picture_rgb24->linesize[3]);
  
  
  
      init_muxer();   // Prepare the GIF encoder (open it on disk).
  
      init_filters(); // Prepare the filter that will be applied over the frame.
  
  
  
      // Instead of hardcoder {1,100} which is the GIF tbn, we collect it from its stream.
  
      // This will avoid future problem if the codec change in ffmpeg.
  
      if (ofmt_ctx &amp;&amp; ofmt_ctx->nb_streams > 0)
  
          m_pts_increment = av_rescale_q(1, { 1, m_framerate }, ofmt_ctx->streams[0]->time_base);
  
      else
  
          m_pts_increment = av_rescale_q(1, { 1, m_framerate }, { 1, 100 });
  
  }
  
  </int>

  FFMPEG Initialization (Filter and muxer)

  void px::GIF::FFMPEG::init_filters()
  
  {
  
      const AVFilter* buffersrc = avfilter_get_by_name("buffer");
  
      const AVFilter* buffersink = avfilter_get_by_name("buffersink");
  
  
  
      AVRational time_base = { 1, m_framerate };
  
      AVRational aspect_pixel = { 1, 1 };
  
  
  
      AVFilterInOut* inputs = avfilter_inout_alloc();
  
      AVFilterInOut* outputs = avfilter_inout_alloc();
  
  
  
      filter_graph = avfilter_graph_alloc();
  
  
  
      try
  
      {
  
          if (!outputs || !inputs || !filter_graph)
  
              throw px::GIF::Error("Failed to 'init_filters' could not allocated the graph/filters.", "GIF::FFMPEG init_filters");
  
  
  
          char args[512];
  
          snprintf(args, sizeof(args),
  
                   "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
  
                   m_width, m_height,
  
                   picture_rgb24->format,
  
                   time_base.num, time_base.den,
  
                   aspect_pixel.num, aspect_pixel.den);
  
  
  
          if (avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in", args, nullptr, filter_graph) < 0)
  
              throw px::GIF::Error("Failed to create the 'source buffer' in init_filer method.", "GIF::FFMPEG init_filters");
  
  
  
  
  
          if (avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out", nullptr, nullptr, filter_graph) < 0)
  
              throw px::GIF::Error("Failed to create the 'sink buffer' in init_filer method.", "GIF::FFMPEG init_filters");
  
  
  
          // GIF has possible output of PAL8.
  
          enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE };
  
  
  
          if (av_opt_set_int_list(buffersink_ctx, "pix_fmts", pix_fmts, AV_PIX_FMT_NONE, AV_OPT_SEARCH_CHILDREN) < 0)
  
              throw px::GIF::Error("Failed to set the output pixel format.", "GIF::FFMPEG init_filters");
  
  
  
          outputs->name = av_strdup("in");
  
          outputs->filter_ctx = buffersrc_ctx;
  
          outputs->pad_idx = 0;
  
          outputs->next = nullptr;
  
  
  
          inputs->name = av_strdup("out");
  
          inputs->filter_ctx = buffersink_ctx;
  
          inputs->pad_idx = 0;
  
          inputs->next = nullptr;
  
  
  
          // GIF has possible output of PAL8. 
  
          if (avfilter_graph_parse_ptr(filter_graph, m_filter_desc.c_str(), &inputs, &outputs, nullptr) < 0)
  
              throw px::GIF::Error("Failed to parse the filter graph (bad string!).", "GIF::FFMPEG init_filters");
  
  
  
          if (avfilter_graph_config(filter_graph, nullptr) < 0)
  
              throw px::GIF::Error("Failed to configure the filter graph (bad string!).", "GIF::FFMPEG init_filters");
  
  
  
          avfilter_inout_free(&inputs);
  
          avfilter_inout_free(&outputs);
  
      }
  
      catch (const std::exception& e)
  
      {
  
          // Catch exception to delete element.
  
          avfilter_inout_free(&inputs);
  
          avfilter_inout_free(&outputs);
  
          throw e; // re-throuw
  
      }
  
  }
  
  
  
  
  
  void px::GIF::FFMPEG::init_muxer()
  
  {
  
      AVOutputFormat* o_fmt = av_guess_format("gif", m_filename.c_str(), "video/gif");
  
  
  
      if ((_ret = avformat_alloc_output_context2(&ofmt_ctx, o_fmt, "gif", m_filename.c_str())) < 0)
  
          throw px::GIF::Error(std::string(av_make_error_string(_err_msg, FFMPEG_MSG_LEN, _ret)) + " allocate output format.", "GIF::FFMPEG init_muxer");
  
  
  
      AVCodec* codec = avcodec_find_encoder(AV_CODEC_ID_GIF);
  
      if (!codec) throw px::GIF::Error("Could to find the 'GIF' codec.", "GIF::FFMPEG init_muxer");
  
  
  
  #if 0
  
      const AVPixelFormat* p = codec->pix_fmts;
  
      while (p != NULL && *p != AV_PIX_FMT_NONE) {
  
          printf("supported pix fmt: %s\n", av_get_pix_fmt_name(*p));
  
          ++p;
  
      }
  
  #endif
  
  
  
      AVStream* stream = avformat_new_stream(ofmt_ctx, codec);
  
  
  
      AVCodecParameters* codec_paramters = stream->codecpar;
  
      codec_paramters->codec_tag = 0;
  
      codec_paramters->codec_id = codec->id;
  
      codec_paramters->codec_type = AVMEDIA_TYPE_VIDEO;
  
      codec_paramters->width = m_width;
  
      codec_paramters->height = m_height;
  
      codec_paramters->format = AV_PIX_FMT_PAL8;
  
  
  
      o_codec_ctx = avcodec_alloc_context3(codec);
  
      avcodec_parameters_to_context(o_codec_ctx, codec_paramters);
  
  
  
      o_codec_ctx->time_base = { 1, m_framerate };
  
  
  
      if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
  
          o_codec_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
  
  
  
      if ((_ret = avcodec_open2(o_codec_ctx, codec, NULL)) < 0)
  
          throw px::GIF::Error(std::string(av_make_error_string(_err_msg, FFMPEG_MSG_LEN, _ret)) + " open output codec.", "GIF::FFMPEG init_muxer");
  
  
  
      if ((_ret = avio_open(&ofmt_ctx->pb, m_filename.c_str(), AVIO_FLAG_WRITE)) < 0)
  
          throw px::GIF::Error(std::string(av_make_error_string(_err_msg, FFMPEG_MSG_LEN, _ret)) + " avio open error.", "GIF::FFMPEG init_muxer");
  
  
  
      if ((_ret = avformat_write_header(ofmt_ctx, NULL)) < 0)
  
          throw px::GIF::Error(std::string(av_make_error_string(_err_msg, FFMPEG_MSG_LEN, _ret)) + " write GIF header", "GIF::FFMPEG init_muxer");
  
  
  
  #if _DEBUG
  
      // This print the stream/output format.
  
      av_dump_format(ofmt_ctx, -1, m_filename.c_str(), 1);
  
  #endif
  
  }

  Add frame (usually in a loop)

  void px::GIF::FFMPEG::add_frame(pxImage * const img)
  
  {
  
      if (img->getImageType() != PXT_BYTE || img->getNChannels() != 4)
  
          throw px::GIF::Error("Failed to 'add_frame' since image is not PXT_BYTE and 4-channels.", "GIF::FFMPEG add_frame");
  
  
  
      if (img->getWidth() != m_width || img->getHeight() != m_height)
  
          throw px::GIF::Error("Failed to 'add_frame' since the size is not same to other inputs.", "GIF::FFMPEG add_frame");
  
  
  
      const int pitch = picture_rgb24->linesize[0];
  
      auto px_ptr = getImageAccessor(img);
  
  
  
      for (int y = 0; y < m_height; y++)
  
      {
  
          const int px_row = img->getOrigin() == ORIGIN_BOT_LEFT ? m_height - y - 1 : y;
  
          for (int x = 0; x < m_width; x++)
  
          {
  
              const int idx = y * pitch + 3 * x;
  
              picture_rgb24->data[0][idx] = px_ptr[px_row][x].ch[PX_RE];
  
              picture_rgb24->data[0][idx + 1] = px_ptr[px_row][x].ch[PX_GR];
  
              picture_rgb24->data[0][idx + 2] = px_ptr[px_row][x].ch[PX_BL];
  
          }
  
      }
  
  
  
      // palettegen need a whole stream, just add frame to buffer.
  
      if ((_ret = av_buffersrc_add_frame_flags(buffersrc_ctx, picture_rgb24, AV_BUFFERSRC_FLAG_KEEP_REF)) < 0)
  
          throw px::GIF::Error("Failed to 'add_frame' to global buffer with error: " +
  
                               std::string(av_make_error_string(_err_msg, FFMPEG_MSG_LEN, _ret)),
  
                               "GIF::FFMPEG add_frame");
  
  
  
      // Increment the FPS of the picture for the next add-up to the buffer.      
  
      picture_rgb24->pts += m_pts_increment;
  
  
  
      as_frame = true;
  
  }    

  Encoder (final step)

  void px::GIF::FFMPEG::encode()
  
  {
  
      if (!as_frame)
  
          throw px::GIF::Error("Please 'add_frame' before running the Encoding().", "GIF::FFMPEG encode");
  
  
  
      // end of buffer
  
      if ((_ret = av_buffersrc_add_frame_flags(buffersrc_ctx, nullptr, AV_BUFFERSRC_FLAG_KEEP_REF)) < 0)
  
          throw px::GIF::Error("error add frame to buffer source: " + std::string(av_make_error_string(_err_msg, FFMPEG_MSG_LEN, _ret)), "GIF::FFMPEG encode");
  
  
  
      do {
  
          AVFrame* filter_frame = av_frame_alloc();
  
          _ret = av_buffersink_get_frame(buffersink_ctx, filter_frame);
  
          if (_ret == AVERROR(EAGAIN) || _ret == AVERROR_EOF) {
  
              av_frame_unref(filter_frame);
  
              break;
  
          }
  
  
  
          // write the filter frame to output file
  
          muxing_one_frame(filter_frame);
  
  
  
          av_frame_unref(filter_frame);
  
      } while (_ret >= 0);
  
  
  
      av_write_trailer(ofmt_ctx);
  
  }
  
  
  
  void px::GIF::FFMPEG::muxing_one_frame(AVFrame* frame)
  
  {
  
      int ret = avcodec_send_frame(o_codec_ctx, frame);
  
      AVPacket *pkt = av_packet_alloc();
  
      av_init_packet(pkt);
  
  
  
      while (ret >= 0) {
  
          ret = avcodec_receive_packet(o_codec_ctx, pkt);
  
          if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
  
              break;
  
          }
  
  
  
          av_write_frame(ofmt_ctx, pkt);
  
      }
  
      av_packet_unref(pkt);
  
  }

  DTOR, Release and Cancel

  px::GIF::FFMPEG::~FFMPEG()
  
  {
  
      release();
  
  }
  
  
  
  
  
  void px::GIF::FFMPEG::release()
  
  {
  
      // Muxer stuffs
  
      if (ofmt_ctx != nullptr) avformat_free_context(ofmt_ctx);
  
      if (o_codec_ctx != nullptr) avcodec_close(o_codec_ctx);
  
      if (o_codec_ctx != nullptr) avcodec_free_context(&o_codec_ctx);
  
  
  
      ofmt_ctx = nullptr;
  
      o_codec_ctx = nullptr;
  
  
  
      // Filter stuffs
  
      if (buffersrc_ctx != nullptr) avfilter_free(buffersrc_ctx);
  
      if (buffersink_ctx != nullptr) avfilter_free(buffersink_ctx);
  
      if (filter_graph != nullptr) avfilter_graph_free(&filter_graph);
  
  
  
      buffersrc_ctx = nullptr;
  
      buffersink_ctx = nullptr;
  
      filter_graph = nullptr;
  
  
  
      // Conversion image.
  
      if (picture_rgb24 != nullptr) av_frame_free(&picture_rgb24);
  
      picture_rgb24 = nullptr;
  
  }
  
  
  
  void px::GIF::FFMPEG::cancel()
  
  {
  
      // In-case of failure we must close ffmpeg and exit.
  
      av_write_trailer(ofmt_ctx);
  
  
  
      // Release and close all elements.
  
      release();
  
  
  
      // Delete the file on disk.
  
      if (remove(m_filename.c_str()) != 0)
  
          PX_LOG0(PX_LOGLEVEL_ERROR, "GIF::FFMPEG - On 'cancel' failed to remove the file.");
  
  }

• ffmpeg determine correct codec to use

  8 avril 2020, par nha

  I am trying to use .y4m files that I feed into Chrome for playing.
This is the only format that I can use.

  



  I have a set of .y4m files that are working for my use case, taken from here.
For example let's say that I use the file mobile_qcif_7.5fps.y4m.

  



  I also have a .mp4 file (specifically the sample small.mp4 file from techslides ). I know how to convert small.mp4 to small.y4m with the following command :

  



  ffmpeg -y -i small.mp4 small.y4m

  



  I would like the resulting file to be accepted by Chrome, just like the other file.
What options should I use (and how to find them) ?

  



  Additional information

  



  ffprobe gives :

  



  $ ffprobe small.y4m 
avprobe version 0.8.13-6:0.8.13-0ubuntu0.13.10.1, Copyright (c) 2007-2014 the Libav developers
  built on Jul 15 2014 13:48:35 with gcc 4.8.1
[yuv4mpegpipe @ 0x23160c0] Estimating duration from bitrate, this may be inaccurate
Input #0, yuv4mpegpipe, from 'small.y4m':
  Duration: N/A, bitrate: N/A
    Stream #0.0: Video: rawvideo, yuv420p, 560x320, 30 fps, 30 tbr, 30 tbn, 30 tbc


$ ffprobe mobile_qcif_7.5fps.y4m
avprobe version 0.8.13-6:0.8.13-0ubuntu0.13.10.1, Copyright (c) 2007-2014 the Libav developers
  built on Jul 15 2014 13:48:35 with gcc 4.8.1
[yuv4mpegpipe @ 0x1e080c0] max_analyze_duration reached
[yuv4mpegpipe @ 0x1e080c0] Estimating duration from bitrate, this may be inaccurate
Input #0, yuv4mpegpipe, from 'mobile_qcif_7.5fps.y4m':
  Duration: N/A, bitrate: N/A
    Stream #0.0: Video: rawvideo, yuv420p, 176x144, PAR 128:117 DAR 1408:1053, 7.50 fps, 7.50 tbr, 7.50 tbn, 7.50 tbc


  



  OS : I am using ffmpeg in Ubuntu 13.10 from the default repository : I ran sudo apt-get install ffmpeg libavcodec-extra-53

  



  Complete console output

  



  $ ffmpeg -y -i small.mp4 small.y4m
ffmpeg version 0.8.13-6:0.8.13-0ubuntu0.13.10.1, Copyright (c) 2000-2014 the Libav developers
  built on Jul 15 2014 13:48:35 with gcc 4.8.1
*** THIS PROGRAM IS DEPRECATED ***
This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'small.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isomavc1
    creation_time   : 2010-03-20 21:29:11
    encoder         : HandBrake 0.9.4 2009112300
  Duration: 00:00:05.56, start: 0.000000, bitrate: 551 kb/s
    Stream #0.0(und): Video: h264 (Constrained Baseline), yuv420p, 560x320, 465 kb/s, 30 fps, 30 tbr, 90k tbn, 60 tbc
    Metadata:
      creation_time   : 2010-03-20 21:29:11
    Stream #0.1(eng): Audio: aac, 48000 Hz, mono, s16, 83 kb/s
    Metadata:
      creation_time   : 2010-03-20 21:29:11
[buffer @ 0x7274e0] w:560 h:320 pixfmt:yuv420p
Output #0, yuv4mpegpipe, to 'small.y4m':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isomavc1
    creation_time   : 2010-03-20 21:29:11
    encoder         : Lavf53.21.1
    Stream #0.0(und): Video: rawvideo, yuv420p, 560x320, q=2-31, 200 kb/s, 90k tbn, 30 tbc
    Metadata:
      creation_time   : 2010-03-20 21:29:11
Stream mapping:
  Stream #0.0 -> #0.0
Press ctrl-c to stop encoding
frame=  166 fps=  0 q=0.0 Lsize=   43576kB time=5.53 bitrate=64513.5kbits/s    
video:0kB audio:0kB global headers:0kB muxing overhead inf%


  



  Head of the files

  



  Not sure if this is relevant, but the text content of both files begin like that :

  



  mobile_qcif_7.5fps.y4m
YUV4MPEG2 W176 H144 F15:2 Ip A128:117
FRAME

small.y4m (invalid)
YUV4MPEG2 W560 H320 F15:2 Ip A0:0 C420mpeg2 XYSCSS=420MPEG2
FRAME


  



  Additional experiment

  



  Taking the sample mobile_qcif_7.5fps.y4m, turning it into a .mp4 file and then back into a .y4m produces an invalid file (at least for Chrome).

  



  Answer to comments in the answer of @SirDarius

  



  Following the suggestion of @SirDarius ; I tried the following commands.
They failed to produce a valid file.

  



  # [COMMAND]   # [RESULT] [HEADER]
ffmpeg -i small.mp4 -vf fps=7.5 -an -c:v rawvideo -f yuv4mpegpipe -pix_fmt yuv444p -y small_yuv444p.y4m   # KO YUV4MPEG2 W560 H320 F15:2 Ip A0:0 C444 XYSCSS=444
ffmpeg -i small.mp4 -vf fps=7.5 -an -c:v rawvideo -f yuv4mpegpipe -pix_fmt yuv422p -y small_yuv422p.y4m   # KO YUV4MPEG2 W560 H320 F15:2 Ip A0:0 C422 XYSCSS=422
ffmpeg -i small.mp4 -vf fps=7.5 -an -c:v rawvideo -f yuv4mpegpipe -pix_fmt yuv420p -y small_yuv420p.y4m   # KO YUV4MPEG2 W560 H320 F15:2 Ip A0:0 C420mpeg2 XYSCSS=420MPEG2
ffmpeg -i small.mp4 -vf fps=7.5 -an -c:v rawvideo -f yuv4mpegpipe -pix_fmt yuv411p -y small_yuv411p.y4m   # KO   YUV4MPEG2 W560 H320 F15:2 Ip A0:0 C411 XYSCSS=411

ffmpeg -i small.mp4 -vf fps=7.5 -an -c:v rawvideo -f yuv4mpegpipe -strict -1 -pix_fmt yuv420p9 -y small_yuv420p9.y4m   # KO YUV4MPEG2 W560 H320 F15:2 Ip A0:0 C420p9 XYSCSS=420P9
ffmpeg -i small.mp4 -vf fps=7.5 -an -c:v rawvideo -f yuv4mpegpipe -strict -1 -pix_fmt yuv420p12 -y small_yuv420p12.y4m # KO YUV4MPEG2 W560 H320 F15:2 Ip A0:0 C420p12 XYSCSS=420P12
ffmpeg -i small.mp4 -vf fps=7.5 -an -c:v rawvideo -f yuv4mpegpipe -strict -1 -pix_fmt yuv420p14 -y small_yuv420p14.y4m # KO YUV4MPEG2 W560 H320 F15:2 Ip A0:0 C420p14 XYSCSS=420P14
ffmpeg -i small.mp4 -vf fps=7.5 -an -c:v rawvideo -f yuv4mpegpipe -strict -1 -pix_fmt yuv420p16 -y small_yuv420p16.y4m # KO YUV4MPEG2 W560 H320 F15:2 Ip A0:0 C420p16 XYSCSS=420P16


  



  When trying other formats (like yuv420p12be, which was in the output of -pix_fmts), I had the following output (hence my previous trials) :

  



  $  ffmpeg -i small.mp4 -vf fps=7.5 -an -c:v rawvideo -f yuv4mpegpipe -pix_fmt yuv420p12be -y small_yuv420p12be.y4m 
ffmpeg version N-68884-g3ebd76a Copyright (c) 2000-2015 the FFmpeg developers
  built on Jan  6 2015 11:03:21 with gcc 4.8 (Ubuntu/Linaro 4.8.1-10ubuntu9)
  configuration: 
  libavutil      54. 16.100 / 54. 16.100
  libavcodec     56. 19.100 / 56. 19.100
  libavformat    56. 18.100 / 56. 18.100
  libavdevice    56.  3.100 / 56.  3.100
  libavfilter     5.  6.100 /  5.  6.100
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  1.100 /  1.  1.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x21d0220] overread end of atom 'colr' by 1 bytes
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'small.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isomavc1
    creation_time   : 2010-03-20 21:29:11
    encoder         : HandBrake 0.9.4 2009112300
  Duration: 00:00:05.57, start: 0.000000, bitrate: 551 kb/s
    Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p(tv, bt709), 560x320, 465 kb/s, 30 fps, 30 tbr, 90k tbn, 60 tbc (default)
    Metadata:
      creation_time   : 2010-03-20 21:29:11
      encoder         : JVT/AVC Coding
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, mono, fltp, 83 kb/s (default)
    Metadata:
      creation_time   : 2010-03-20 21:29:11
[yuv4mpegpipe @ 0x21d8180] ERROR: yuv4mpeg can only handle yuv444p, yuv422p, yuv420p, yuv411p and gray8 pixel formats. And using 'strict -1' also yuv444p9, yuv422p9, yuv420p9, yuv444p10, yuv422p10, yuv420p10, yuv444p12, yuv422p12, yuv420p12, yuv444p14, yuv422p14, yuv420p14, yuv444p16, yuv422p16, yuv420p16 and gray16 pixel formats. Use -pix_fmt to select one.
Output #0, yuv4mpegpipe, to 'small_yuv420p12be.y4m':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42isomavc1
    encoder         : Lavf56.18.100
    Stream #0:0(und): Video: rawvideo ([12][11]3Y / 0x59330B0C), yuv420p12be, 560x320, q=2-31, 200 kb/s, 7.50 fps, 7.50 tbn, 7.50 tbc (default)
    Metadata:
      creation_time   : 2010-03-20 21:29:11
      encoder         : Lavc56.19.100 rawvideo
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> rawvideo (native))
Could not write header for output file #0 (incorrect codec parameters ?): Input/output error


  



  After that, I also tried to edit with an hexadecimal editor (bless) the small_yuv420p.y4m file. I replace C420mpeg2 by C420, and the file was accepted by Chrome.
What does the number in 420p[number] correspond to ? It is not explained there.
Is there any way to make ffmpeg output this kind of header files ?

  



  @SirDarius, thank you again for your help.

  



  The question

  



  (in case you forgot after this text blob)

  



  How can I convert the small.mp4 into a small.y4m file that has the same properties as the mobile_qcif_7.5fps.y4m file ?

  


• Python script creates too short video using ffmpeg

  25 mai 2014, par Majzlik

  I use python script to create multiple pictures and call ffmpeg to create video. But there is a problem, because ffmpeg use just few pictures (about 7 - 10 from 160), but throws no error. I’ve tried the same command from commandline and video was correct. I’m calling ffmpeg this way :

  ffmpeg_call = ["ffmpeg", "-r", str(FPS), "-b", "16777216", "-y", "-i", "./sample_%05d.png", FILEOUTNAME + ".mp4"]
  
  subprocess.call(ffmpeg_call)

  and this was command in commandline :

  ffmpeg -r 25 -b 16777216 -y -i ./sample_%05d.png animation.mp4

  I’ve printed these commands to compare and they were the same, so there has to be problem in ffmpeg + python cooperation. Don’t you know, how to fix it ?

  UPDATE :

  this is log from ffmpeg :

  ffmpeg version 0.8.10-4:0.8.10-0ubuntu0.12.04.1, Copyright (c) 2000-2013 the Libav     developers
  
    built on Feb  6 2014 20:56:59 with gcc 4.6.3
  
  *** THIS PROGRAM IS DEPRECATED ***
  
  This program is only provided for compatibility and will be removed in a future release. Please use avconv instead.
  
  Input #0, image2, from '/tmp/tmpRKxT6s/ampgraph/tmp/sample_%05d.png':
  
  Duration: 00:00:00.44, start: 0.000000, bitrate: N/A
  
  Stream #0.0: Video: png, pal8, 640x480, 25 fps, 25 tbr, 25 tbn, 25 tbc
  
  Incompatible pixel format 'pal8' for codec 'mpeg4', auto-selecting format 'yuv420p'
  
  [buffer @ 0x19e18a0] w:640 h:480 pixfmt:pal8
  
  [avsink @ 0x19ee1c0] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'out'
  
  [scale @ 0x19e2fc0] w:640 h:480 fmt:pal8 -> w:640 h:480 fmt:yuv420p flags:0x4
  
  Output #0, mp4, to './ampgraph/animation.mp4':
  
    Metadata:
  
      encoder         : Lavf53.21.1
  
      Stream #0.0: Video: mpeg4, yuv420p, 640x480, q=2-31, 200 kb/s, 25 tbn, 25 tbc
  
  Stream mapping:
  
    Stream #0.0 -> #0.0
  
  Press ctrl-c to stop encoding
  
  frame=   11 fps=  0 q=2.5 Lsize=      46kB time=0.44 bitrate= 859.1kbits/s    
  
  video:45kB audio:0kB global headers:0kB muxing overhead 1.906569%