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• MP4 file starts from a non-key frame [closed]

  1er octobre 2023, par userDtrm

  I have used the following ffprobe command to analyse a .mp4 file.

  


  


  ffprobe -i <input /> -show_frames - select_streams v:0 -print_format flat &amp;> save_to_file.text

  


  


  It produces the following output.

  


  

    ffprobe version 5.1.3 Copyright (c) 2007-2022 the FFmpeg developers
      built with gcc 13 (GCC)
      configuration : —prefix=/home/thanuja/ffmpeg_build —pkg-config-flags=—static —extra-cflags=-I/home/thanuja/ffmpeg_build/include —extra-ldflags=-L/home/thanuja/ffmpeg_build/lib —extra-libs=-lpthread —extra-libs=-lm —bindir=/home/thanuja/bin —enable-gpl —enable-libfdk_aac —enable-libfreetype —enable-libmp3lame —enable-libopus —enable-libvpx —enable-libx264 —enable-libx265 —enable-nonfree —enable-openssl —enable-demuxer=spdif —enable-decoder=dolby_e —enable-decoder=ac3 —enable-decoder=eac3 —enable-indev=alsa —enable-outdev=alsa —enable-shared
      libavutil      57. 28.100 / 57. 28.100
      libavcodec     59. 37.100 / 59. 37.100
      libavformat    59. 27.100 / 59. 27.100
      libavdevice    59.  7.100 / 59.  7.100
      libavfilter     8. 44.100 /  8. 44.100
      libswscale      6.  7.100 /  6.  7.100
      libswresample   4.  7.100 /  4.  7.100
      libpostproc    56.  6.100 / 56.  6.100
    Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'FTV267StoS.mp4' :
      Metadata :
        major_brand : mp42
        minor_version : 1
        compatible_brands : isommp41mp42
        creation_time : 2023-04-02T23:52:12.000000Z
      Duration : 00:04:47.84, start : 0.000000, bitrate : 7374 kb/s
      Stream #0:0[0x1](und) : Video : h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709/unknown/bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 7198 kb/s, 59.94 fps, 59.94 tbr, 90k tbn (default)
        Metadata :
          creation_time : 2023-04-02T23:52:12.000000Z
          handler_name : Core Media Video
          vendor_id : [0][0][0][0]
      Stream #0:1[0x2](eng) : Audio : aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 125 kb/s (default)
        Metadata :
          creation_time : 2023-04-02T23:52:12.000000Z
          handler_name : Core Media Audio
          vendor_id : [0][0][0][0]
    frames.frame.0.media_type="video"
    frames.frame.0.stream_index=0
    frames.frame.0.key_frame=0
    frames.frame.0.pts=34536
    frames.frame.0.pts_time="0.383733"
    frames.frame.0.pkt_dts=34536
    frames.frame.0.pkt_dts_time="0.383733"
    frames.frame.0.best_effort_timestamp=34536
    frames.frame.0.best_effort_timestamp_time="0.383733"
    frames.frame.0.pkt_duration=1501
    frames.frame.0.pkt_duration_time="0.016678"
    frames.frame.0.pkt_pos="1834827"
    frames.frame.0.pkt_size="14917"
    frames.frame.0.width=1920
    frames.frame.0.height=1080
    frames.frame.0.pix_fmt="yuv420p"
    frames.frame.0.sample_aspect_ratio="1:1"
    frames.frame.0.pict_type="P"
    frames.frame.0.coded_picture_number=120
    frames.frame.0.display_picture_number=0
    frames.frame.0.interlaced_frame=0
    frames.frame.0.top_field_first=0
    frames.frame.0.repeat_pict=0
    frames.frame.0.color_range="tv"
    frames.frame.0.color_space="bt709"
    frames.frame.0.color_primaries="unknown"
    frames.frame.0.color_transfer="bt709"
    frames.frame.0.chroma_location="left"
    frames.frame.0.tags.timecode="20:18:26:50"
    frames.frame.0.side_data_list.side_data.0.side_data_type="H.26[45] User Data Unregistered SEI message"
    frames.frame.0.side_data_list.side_data.1.side_data_type="H.26[45] User Data Unregistered SEI message"
    frames.frame.0.side_data_list.side_data.2.side_data_type="SMPTE 12-1 timecode"
    frames.frame.0.side_data_list.side_data.2.timecodes.timecode.0.value="20:18:26:50"
    frames.frame.1.media_type="video"
    frames.frame.1.stream_index=0
    frames.frame.1.key_frame=0
    frames.frame.1.pts=36036
    frames.frame.1.pts_time="0.400400"
    frames.frame.1.pkt_dts=36036
    frames.frame.1.pkt_dts_time="0.400400"
    frames.frame.1.best_effort_timestamp=36036
    frames.frame.1.best_effort_timestamp_time="0.400400"
    frames.frame.1.pkt_duration=1501
    frames.frame.1.pkt_duration_time="0.016678"
    frames.frame.1.pkt_pos="1857434"
    frames.frame.1.pkt_size="14472"
    frames.frame.1.width=1920
    frames.frame.1.height=1080
    frames.frame.1.pix_fmt="yuv420p"
    frames.frame.1.sample_aspect_ratio="1:1"
    frames.frame.1.pict_type="P"



  


  As seen in this output, the 1st frame appears to be a P frame. I'm curious as to how will the decoder decode this frame without a preceding I frame (key frame) ? The P frame will not have enough information to reconstruct the image from its residual data without the key frame.

  


• App Intents FFmpeg-iOS operation not permitted

  2 octobre 2023, par apo_p9

  Using latest iOS and Xcode, I have an AppIntent to which Im passing a video file from iOS Shortcuts, Im using an IntentFile parameter to read that in the intent. Then Im using FFmpeg-iOS to generate a single frame from the video.

  


  ...
@Parameter(title: "Media", supportedTypeIdentifiers: ["public.image", "public.video"], inputConnectionBehavior: .connectToPreviousIntentResult)
var media: IntentFile
...
let mediaPath = media.fileURL!.absoluteString;
let posterPath = mediaPath.replacingOccurrences(of: media.filename, with: "poster.jpg")
_ = ffmpeg(["FFmpeg-iOS", "-i", mediaPath, "-frames:v", "1", posterPath])


  


  Here is the output :

  


  ffmpeg(_:) ["FFmpeg-iOS", "-i", "file:///var/mobile/tmp/com.apple.WorkflowKit.BackgroundShortcutRunner/IMG_2751.mov", "-frames:v", "1", "file:///var/mobile/tmp/com.apple.WorkflowKit.BackgroundShortcutRunner/poster.jpg"]
ffmpeg version N-109970-g7dc0944ce2 Copyright (c) 2000-2023 the FFmpeg developers
  built with Apple clang version 14.0.0 (clang-1400.0.29.202)
  configuration: --prefix=/Users/changbeomahn/Projects/FFmpeg-iOS/build/install/FFmpeg/arm64 --enable-cross-compile --disable-debug --disable-doc --enable-pic --disable-audiotoolbox --disable-sdl2 --disable-libxcb --target-os=darwin --arch=arm64 --cc='xcrun -sdk iphoneos clang' --as='gas-preprocessor.pl -arch aarch64 -- xcrun -sdk iphoneos clang' --extra-cflags='-arch arm64 -mios-version-min=13.0 -I/Users/changbeomahn/Projects/FFmpeg-iOS/build/install/FFmpeg/arm64/include' --extra-ldflags='-arch arm64 -mios-version-min=13.0 -L/Users/changbeomahn/Projects/FFmpeg-iOS/build/install/FFmpeg/arm64/lib'
HookMain: setjmp=0
FFmpeg_exit=1, will longjmp
HookMain: setjmp=1
  libavutil      58.  3.100 / 58.  3.100
  libavcodec     60.  6.100 / 60.  6.100
  libavformat    60.  4.100 / 60.  4.100
  libavdevice    60.  2.100 / 60.  2.100
  libavfilter     9.  4.100 /  9.  4.100
  libswscale      7.  2.100 /  7.  2.100
  libswresample   4. 11.100 /  4. 11.100
file:///var/mobile/tmp/com.apple.WorkflowKit.BackgroundShortcutRunner/IMG_2751.mov: Operation not permitted


  


  The issue is in the last line : Operation not permitted

  


  I also tried just writing a file to the same directory as the media file :

  


  let str = "Super long string here"
let filename = media.fileURL!.absoluteString.replacingOccurrences(of: media.filename, with: "asd.txt")

do {
    try str.write(to: URL(string: filename)!, atomically: true, encoding: String.Encoding.utf8)
} catch {
    print(error)
}


  


  But got the error :

  


  Error Domain=NSCocoaErrorDomain Code=513 "You don’t have permission to save the file “asd.txt” in the folder “com.apple.WorkflowKit.BackgroundShortcutRunner”." UserInfo={NSFilePath=/var/mobile/tmp/com.apple.WorkflowKit.BackgroundShortcutRunner/asd.txt, NSUnderlyingError=0x280f09aa0 {Error Domain=NSPOSIXErrorDomain Code=1 "Operation not permitted"}}


  


  Apparently there is a permission issue, I tried googling about "AppIntents file permissions"/"shortcut permissions"/etc but found nothing. Im not a mobile developer so Im totally clueless. The same code though works fine in the simulator, it gets the permission issue only on device.

  


• FFmpeg does not encode chapter titles [closed]

  15 octobre 2023, par Shironats

  I am trying to add chapters to a .mp4 file.
When I tried extracting the metadata using the following command :

  


  ffmpeg -i INPUT.mp4 -f ffmetadata FFMETADATAFILE.txt

  


  I got an output file as follows :

  


  ;FFMETADATA1
major_brand=mp42
minor_version=0
compatible_brands=isommp42
encoder=Lavf60.15.100


  


  So now I try to add some chapters as such

  


  [CHAPTER]
TIMEBASE=1/1000
START=0
END=424510
title=mytitle1

[CHAPTER]
TIMEBASE=1/1000
START=424511
END=941600
title=mytitle2

[CHAPTER]
TIMEBASE=1/1000
START=941601
END=1227260
title=mytitle3


  


  I use the ffmpeg -i INPUT.mp4 -i FFMETADATAFILE.txt -map_metadata 1 -codec copy OUTPUT.mp4 command to encode the metadata to my video file, and for some reason I only ever get 'Chapter 0', 'Chapter 1', and 'Chapter 2'.

  


  I tried using the -map_chapters 1 argument as well but results have been unchanged.

  


  I am using the Latest Auto-Build (2023-10-14 13:02) Windows build by BtbN. Thanks in advance for the help.