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• How to use ffmpeg to stream a playlist of clips that are in very different formats ? [closed]

  21 septembre 2024, par gulagkulak

  I'm trying to use ffmpeg to stream a playlist of video files that are all in very different formats, sizes, and aspect ratios.

  


  The problem is that often when the video changes I get a spinning wheel of death on the target streaming sites and some kinda error in the ffmpeg output.

  


  Sometimes it's [flv @ 0x7f5c10686200] Failed to update header with correct duration.

  


  Or [flv @ 0x7f5c10686200] Failed to update header with correct filesize.

  


  Or a whole bunch of [aost#0:1/aac @ 0x8947680] Non-monotonic DTS; previous: 82536459, current: 78988751; changing to 82536460. This may result in incorrect timestamps in the output file.

  


  Or it starts dropping every single frame. I think it happens when it changes from a progressive to deinterlaced file or vice-versa.

  


  How do I make ffmpeg more resilient so it can handle every kind of file thrown at it and output a continuous stream at 1920x1080 and 30fps h264 to a streaming server ?

  


  This is the command I'm using :

  


  ffmpeg -stream_loop -1 -re -f concat -i playlist.txt -threads 4 -c:v libx264 -preset ultrafast \
-b:v 2000k -maxrate 2000k -g 30 -c:a aac -b:a 128k -strict -2 -fflags +genpts+discardcorrupt \
-async 1 -map 0 -r 30 -s 1920x1080 -bufsize 6000k -flags +cgop -fflags +igndts \
-f tee -rtsp_transport tcp -max_delay 1000 \
"[f=flv:onfail=ignore]rtmp://xxxxxxxxxxxxxxx.com/live/xxxxxxxxxxxxxxx|[f=flv:onfail=ignore]rtmp://xxxxxxxxxxxxxxx.com/live/xxxxxxxxxxxxxxx"


  


  And it's not working. ffmpeg just fails in a variety of ways. I've spent two days trying to figure this out.

  


  Even used handbrake to try and pre-encode the video files to the same exact format, but even then ffmpeg fails in similar ways, just less often.

  


  After re-encoding with handbrake I tried to concat the videos together with ffmpeg and ended up with a large video where the sound breaks for some parts of it and it stops being seekable in VLC after a certain timecode.

  


  I think I'm missing some important ffmpeg flag or option.

  


• Inserting clips into mp4 via ffmpeg

  15 septembre 2024, par lfgan

  I am looking to create mp4 files by combining multiple static mp4s and mp3s.
I have a script already to convert mp3 to mp4 and using the album art as a static background image, and inserting the intro.
What I am having problems with is that it cannot concatenate the videos reliably, or at all for that matter.

  


  This is the code that I currently have, it is ChatGPT, however I gave up as it seemed like it was just running in circles.

  


  setlocal

:: Set variables
set "mp3file=myfile.mp3"
set "coverart=extracted_cover.jpg"
set "outputfile=music.mp4"
set "introfile=intro.mp4"
set "outputendfile=Outro.mp4"
set "wowfile=Wow!.mp4"

:: Step 1: Extract cover art from MP3
ffmpeg -i "%mp3file%" -an -vcodec copy "%coverart%"
if %errorlevel% neq 0 (
    echo Error: Failed to extract cover art from MP3 file.
    exit /b 1
)

:: Step 2: Convert MP3 to MP4 using the extracted cover art
ffmpeg -loop 1 -i "%coverart%" -i "%mp3file%" -c:v libx264 -tune stillimage -c:a aac -b:a 192k -shortest "%outputfile%"
if %errorlevel% neq 0 (
    echo Error: Conversion from MP3 to MP4 failed.
    exit /b 1
)

:: Step 3: Randomly generate two positions for Wow!.mp4 insertions
:: Random positions will be between 10 and 50 seconds
set /a "pos1=%random% %% 40 + 10"
set /a "pos2=%random% %% 40 + 10"

:: Ensure pos1 and pos2 are different
if %pos1% EQU %pos2% (
    set /a "pos2=%pos1%+10"
)

:: Print positions for debugging
echo Random insertion positions:
echo Position 1: %pos1%
echo Position 2: %pos2%

:: Step 4: Split the music mp4 into parts at the random positions
:: Part 1: From the beginning to pos1
ffmpeg -i "%outputfile%" -c copy -ss 0 -to %pos1% -y "part1.mp4"
if not exist "part1.mp4" (
    echo Error: Failed to create part1.mp4
    exit /b 1
)

:: Part 2: From pos1 to pos2
ffmpeg -i "%outputfile%" -c copy -ss %pos1% -to %pos2% -y "part2.mp4"
if not exist "part2.mp4" (
    echo Error: Failed to create part2.mp4
    exit /b 1
)

:: Part 3: From pos2 to the end
ffmpeg -i "%outputfile%" -c copy -ss %pos2% -y "part3.mp4"
if not exist "part3.mp4" (
    echo Error: Failed to create part3.mp4
    exit /b 1
)

:: Step 5: Concatenate the files in the required order
(
    echo file 'intro.mp4'
    echo file 'part1.mp4'
    echo file 'Wow!.mp4'
    echo file 'part2.mp4'
    echo file 'Wow!.mp4'
    echo file 'part3.mp4'
    echo file 'Outro.mp4'
) > concat_list.txt

ffmpeg -f concat -safe 0 -i concat_list.txt -c copy final_output.mp4
if %errorlevel% neq 0 (
    echo Error: Failed to concatenate the video files.
    exit /b 1
)

:: Cleanup
del part1.mp4 part2.mp4 part3.mp4 concat_list.txt "%coverart%"

echo Done! The final video is saved as final_output.mp4


  


  exactly what it is supposed to do :

  


  

  1. Convert "myfile.mp3" to "music.mp4" with image (works)

  


  2. Add "intro.mp4" to the start of "music.mp4" and "Output.mp4" to the end (works)

  


  3. Split "music.mp4" into 3 parts, randomly, at a minimum 10s after intro.mp4 and 10s before Outro.mp4 (can for some reason only create part 1)

  


  4. Put all clips in order (unknown, probably works but part 2 and 3 wont generate so it cannot get to that step.)

  


  


  Edit :
I forgot to add the error message that I am getting. Here it is :

  


  [out#0 @ 000002e024a6ed00] -to value smaller than -ss; aborting.
Error opening output file part2.mp4.
Error opening output files: Invalid argument
Error: Failed to create part2.mp4


  


• lavu/riscv : implement floating point clips

  25 juillet 2024, par Rémi Denis-Courmont

  lavu/riscv : implement floating point clips
  Unlike x86, fmin/fmax are single instructions, not function calls. They
  
  are much much faster than doing a comparison, then branching based on its
  
  results. With this, audiodsp.vector_clipf gets almost twice as fast, and
  
  a properly unrollled version of it gets 4-5x faster, on SiFive-U74.
  
  This is only the low-hanging fruit : FFMIN and FFMAX are presumably
  
  affected as well.
  This likely applies to other instruction sets with native IEEE floats,
  
  especially those lacking a conditional select instruction.
  

  • [DH] libavutil/riscv/intmath.h