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• How to encode HEVC HDR10 to SVT-AV1 HDR10 ?

  28 octobre 2022, par Mario Gratzi

  I'm currently trying to find a way to re-encode a HEVC HDR10 clip to SVT-AV1 HDR10 using ffmpeg but for some reason, I don't get ffmpeg to forward the HDR metadata to the AV1 clip. So the re-encoded AV1 clip always has very cold color grading, which does not make fun to watch at all...

  


  I then checked onto FastFlix, a similar tool to Handbrake which is basically a ffmpeg frontend. If I select SVT-AV1 as encoder here, and I check onto the raw ffmpeg command FastFlix generates, it seems that this also includes the grading information :

  


  -svtav1-params "color-primaries=9:transfer-characteristics=16:matrix-coefficients=9:mastering-display=G(0.2650,0.6900)B(0.1500,0.0600)R(0.6800,0.3200)WP(0.3127,0.3290)L(4000.0000,0.0050):content-light=368,226:enable-hdr=1"


  


  The problem for me is now, how do I get these grading information with my own ffmpeg command ?

  


• Creating iPhone compatible video with ffmpeg from an image and MP3 file

  22 février 2020, par Gracie

  I have the following command that I have used to create an MP4 video file from an image and an MP3 file, it plays fine in a Chrome browser on desktop and on an Android phone - but it doesn’t work on an iPhone 10. Do I need some extra codec or setting to make this compatible for iPhone ? Should I be converting this into a MPEG file instead for wider compatibility ?

  ffmpeg -loop 1 -i 6f4aa5dfefc4dd32186f41315ad9d1e2-0.png -i "music.mp3" -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest aa-image0.mp4

  Here are the ffprobe details for the input MP3 file used to create the MP4 video and also the ffprobe for that output file :

  Input #0, wav, from 'download0.mp3':
  
    Duration: 00:00:35.94, bitrate: 384 kb/s
  
      Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 24000 Hz, 1 channels, s16, 384 kb/s

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'aa-image0.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf58.22.100
  
    Duration: 00:00:38.76, start: 0.000000, bitrate: 505 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 2664x1498 [SAR 1:1 DAR 1332:749], 367 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, mono, fltp, 138 kb/s (default)
  
      Metadata:
  
        handler_name    : SoundHandler

  The video seems to play on the iPhone, but the audio seems to start/stop constantly. Like it is a streaming issue (even though it is not). Maybe an MP3 encoding issue when I created the video ?

  Here are the test files I have used and created (any iPhone users will likely find the MP4 will not play the audio in the video properly) :

  https://ffmpeg-iphone-issue.netlify.com/tesla.jpg

  https://ffmpeg-iphone-issue.netlify.com/tesla.mp3

  https://ffmpeg-iphone-issue.netlify.com/tesla.mp4 (OUTPUT - Created from the 2 files above)

  ---

  In summary, two FFmpeg commands are required :

  1) Used to create iPhone/iOS compatible videos in FFmpeg from an image and MP3 (A slight modification to the command at the top of the page)

  and

  2) An FFmpeg command that could be used to fix or re-encode the video above so that it works on iPhone (A new command incorporating the parts so it works with iPhone and then to rebuild and fix the "broken" video. In a similar fashion to this video where he fixes a broken video https://www.youtube.com/watch?v=2FhmbKKh6mc [command in Youtube description])

• ffmpeg audio is stuttering when converting from h264 to mpeg2

  9 février 2019, par user11038211

  I want to convert from h264 stream source (streamlink) to mpeg2 video and send it to a DVB-T modulator (Hides UT100C). So far, I have managed to play the video smoothly, but audio is jerky. It sounds like parts are missing. I think that some parameters are not set perfectly :

  $streamlink -O https://zattoo.com/watch/orf-2 best | ffmpeg -re -i pipe:0 -vcodec mpeg2video -s 720x576 -r 30 -b:v 10M -b:a 64k -acodec mp2 -mpegts_original_network_id 1 -mpegts_transport_stream_id 1 -mpegts_service_id 1 -mpegts_pmt_start_pid 1000 -mpegts_start_pid 1001 -metadata service_provider="HOME" -metadata service_name="IPTV" -muxrate 10M -f mpegts -y tspipe | sudo ./tsrfsend tspipe 0 578000 8000 4 1/2 1/4 8 0 0
  
  
  
  [cli][info] Found matching plugin zattoo for URL https://zattoo.com/watch/orf-2
  
  [cli][info] Available streams: 600k_alt (worst), 600k, 900k, 1500k (best)
  
  [cli][info] Opening stream: 1500k (hls)
  
  Input #0, mpegts, from 'pipe:0':
  
    Duration: N/A, start: 45236.000000, bitrate: N/A
  
    Program 1
  
      Stream #0:0[0x100]: Video: h264 (Main) ([27][0][0][0] / 0x001B), yuv420p(progressive), 768x432 [SAR 1:1 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc
  
      Stream #0:1[0x101]: Audio: aac (LC) ([15][0][0][0] / 0x000F), 48000 Hz, stereo, fltp, 128 kb/s
  
  
  
  Open /dev/usb-it950x0 ok
  
  g_ITEAPI_TxDeviceInit ok
  
  1 Devices
  
  g_ITEAPI_GetDrvInfo ok
  
  DriverInfo.DriverVerion  = v16.11.10.1
  
  DriverInfo.APIVerion     = 1.3.20160929.0
  
  DriverInfo.FWVerionLink  = 255.39.2.0
  
  DriverInfo.FWVerionOFDM  = 255.9.11.0
  
  DriverInfo.Company       = ITEtech
  
  DriverInfo.SupportHWInfo = Eagle DVBT
  
  DriverInfo.ProductID     = 0x9507
  
  Frequency = 578000 KHz
  
  Bandwidth = 8000 MHz
  
  Constellation: QPSK
  
  Code Rate: 1/2
  
  Interval: 1/4
  
  Transmission Mode: 8K
  
  Output #0, mpegts, to 'tspipe':
  
    Metadata:
  
      service_provider: HOME
  
      service_name    : IPTV
  
      encoder         : Lavf57.56.101
  
      Stream #0:0: Video: mpeg2video (Main), yuv420p, 720x576 [SAR 64:45 DAR 16:9], q=2-31, 10000 kb/s, 30 fps, 90k tbn, 30 tbc
  
      Metadata:
  
        encoder         : Lavc57.64.101 mpeg2video
  
      Side data:
  
        cpb: bitrate max/min/avg: 0/0/10000000 buffer size: 0 vbv_delay: -1
  
      Stream #0:1: Audio: mp2, 48000 Hz, stereo, s16, 64 kb/s
  
      Metadata:
  
        encoder         : Lavc57.64.101 mp2
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 (native) -> mpeg2video (native))
  
    Stream #0:1 -> #0:1 (aac (native) -> mp2 (native))
  
  Channel Capacity is 4976172 bps
  
  MinGain: -52, MaxGain: 5
  
  frame=    3 fps=0.0 q=2.0 size=      63kB time=00:00:00.38 bitrate=1337.3kbits/s

  Tsrfsend is the application that sends the generated ts stream over a named pipe to the USB modulator.

  I also tried various audio bitrates such as 64, 192, 384k but all is very similar.