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• Batch process audio files and image files to create movie files by matching multiple wildcard values

  29 septembre 2022, par psychaudio

  I'm attempting to batch-process audio and image files to create video files using a Shell script with FFmpeg.

  


  

  1. The ffmpeg script works in Terminal :

  


  


  ffmpeg -loop 1 -i image.png -i audio.wav -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest output.mp4


  


  

  2. A nested for loop with wildcards works as a batch script :

  


  


  #!/bin/sh
for img in *.png; do
    for wav in *.wav; do
        ffmpeg -loop 1 -i $img -i $wav -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest ../mb/$img.mp4
    done
done


  


  The only problem here is that it creates more combinations than I need. I'd like to be able to match wildcard values and only mix those together. I'd like to be able to prepare the filenames to match in advance to make this easier : For example, only match 1.png with 1.wav to make 1.mp4, 2.png with 2.wav to make 2.mp4 and so on. I'm able to modify the script to match the wildcards in a Regex, but I'm not sure if there is a way to then execute the logic above. Here is what I am attempting :

  


  #!/bin/sh
img=*.png
wav=*.wav

if [[ ${img%.*} == ${wav%.*} ]];
    then
        ffmpeg -loop 1 -i $img -i $wav -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest $img.mp4;
    else
        echo "Failure"
    fi


  


  This begins by overwriting the image files, so it does not appear to work as planned. Is there a simpler way to do this ? Perhaps looping through images 1..5 in one folder and audio files 1..5 in another ?

  


  Thanks for any insights, and happy to provide more context (very new to this, so still learning).

  


• Convert MPEG4 to MPEGTS on Android with FFmpeg

  3 juin 2013, par Ardoramor

  Ok, so obviously I know very little to none about ffmpeg API when I made the original post... it is quite overwhelming when one starts learning about digital media and conversion details. After reading quite a bit more and going through ffmpeg source, I was able to get a working output from mp4 to mpegts. The concept is similar to executing :

  ffmpeg -i in.mp4 -vcodec copy -acodec copy -vbsf h264_mp4toannexb out.ts

  But as I mentioned before, I need to implement it with ffmpeg API in C.

  So, although I am able to generate a playable .ts file, its video and audio streams are not synced. That is, playing them back on Android tablet plays the video very slowly while audio is playing at normal speed and then (once audio stream ends) video plays at normal speed to the end. Playing the same generated .ts file in VLC produces a very condensed audio (as though fast-forwarded) and plays video fine.

  There are still many aspects of media conversion that I am not familiar with. I am sure that some of them prevent me from successful conversion.

  Here is some information (via ffprobe) about the files :
   in.mp4 - file generated via Android recording - MPEG4 (H.264 + AAC)
   ffmpeg.ts - file generated via ffmpeg conversion - MPEG2TS (H.264 + AAC)
   out.ts - file generated via my code - MPEGTS (H.264 + AAC)

  in.mp4

  filename=in.mp4
  
  nb_streams=2
  
  format_name=mov,mp4,m4a,3gp,3g2,mj2
  
  format_long_name=QuickTime/MPEG-4/Motion JPEG 2000 format
  
  start_time=0:00:00.000000
  
  duration=0:00:09.961383
  
  size=4.730 Mibyte
  
  bit_rate=3.983 Mbit/s
  
  TAG:major_brand=isom
  
  TAG:minor_version=0
  
  TAG:compatible_brands=isom3gp4
  
  TAG:creation_time=2013-05-28 17:06:57

  ffmpeg.ts

  filename=ffmpeg.ts
  
  nb_streams=2
  
  format_name=mpegts
  
  format_long_name=MPEG-2 transport stream format
  
  start_time=0:00:01.400000
  
  duration=0:00:09.741267
  
  size=5.132 Mibyte
  
  bit_rate=4.419 Mbit/s

  out.ts

  filename=out.ts
  
  nb_streams=2
  
  format_name=mpegts
  
  format_long_name=MPEG-2 transport stream format
  
  start_time=0:00:00.000000
  
  duration=0:00:09.741267
  
  size=5.166 Mibyte
  
  bit_rate=4.449 Mbit/s

  Firstly, I was unable to affect my output file's start_time. Next, upon examining the -show_packets output of probe, I saw the following :

  ffmpeg.ts

  [PACKET]
  
  codec_type=video
  
  stream_index=0
  
  pts=N/A
  
  pts_time=N/A
  
  dts=N/A
  
  dts_time=N/A
  
  duration=0
  
  duration_time=0:00:00.000000
  
  size=20.506 Kibyte
  
  pos=564
  
  flags=K
  
  [/PACKET]
  
  [PACKET]
  
  codec_type=video
  
  stream_index=0
  
  pts=N/A
  
  pts_time=N/A
  
  dts=N/A
  
  dts_time=N/A
  
  duration=0
  
  duration_time=0:00:00.000000
  
  size=11.727 Kibyte
  
  pos=22936
  
  flags=_
  
  [/PACKET]
  
  ...
  
  [PACKET]
  
  codec_type=audio
  
  stream_index=1
  
  pts=126000
  
  pts_time=0:00:01.400000
  
  dts=126000
  
  dts_time=0:00:01.400000
  
  duration=2089
  
  duration_time=0:00:00.023211
  
  size=285.000 byte
  
  pos=109416
  
  flags=K
  
  [/PACKET]
  
  [PACKET]
  
  codec_type=audio
  
  stream_index=1
  
  pts=128089
  
  pts_time=0:00:01.423211
  
  dts=128089
  
  dts_time=0:00:01.423211
  
  duration=2089
  
  duration_time=0:00:00.023211
  
  size=374.000 byte
  
  pos=-1
  
  flags=K
  
  [/PACKET]
  
  ...
  
  [PACKET]
  
  codec_type=video
  
  stream_index=0
  
  pts=N/A
  
  pts_time=N/A
  
  dts=N/A
  
  dts_time=N/A
  
  duration=0
  
  duration_time=0:00:00.000000
  
  size=20.000 Kibyte
  
  pos=87232
  
  flags=_
  
  [/PACKET]
  
  [PACKET]
  
  codec_type=video
  
  stream_index=0
  
  pts=N/A
  
  pts_time=N/A
  
  dts=N/A
  
  dts_time=N/A
  
  duration=0
  
  duration_time=0:00:00.000000
  
  size=16.852 Kibyte
  
  pos=112800
  
  flags=_
  
  [/PACKET]

  out.ts

  [PACKET]
  
  codec_type=audio
  
  stream_index=1
  
  pts=0
  
  pts_time=0:00:00.000000
  
  dts=0
  
  dts_time=0:00:00.000000
  
  duration=2089
  
  duration_time=0:00:00.023211
  
  size=285.000 byte
  
  pos=22936
  
  flags=K
  
  [/PACKET]
  
  [PACKET]
  
  codec_type=audio
  
  stream_index=1
  
  pts=1024
  
  pts_time=0:00:00.011378
  
  dts=1024
  
  dts_time=0:00:00.011378
  
  duration=2089
  
  duration_time=0:00:00.023211
  
  size=374.000 byte
  
  pos=23312
  
  flags=K
  
  [/PACKET]
  
  ...
  
  
  
  [PACKET]
  
  codec_type=video
  
  stream_index=0
  
  pts=N/A
  
  pts_time=N/A
  
  dts=N/A
  
  dts_time=N/A
  
  duration=0
  
  duration_time=0:00:00.000000
  
  size=11.727 Kibyte
  
  pos=25004
  
  flags=_
  
  [/PACKET]
  
  [PACKET]
  
  codec_type=audio
  
  stream_index=1
  
  pts=7168
  
  pts_time=0:00:00.079644
  
  dts=7168
  
  dts_time=0:00:00.079644
  
  duration=2089
  
  duration_time=0:00:00.023211
  
  size=299.000 byte
  
  pos=55460
  
  flags=K
  
  [/PACKET]

  As you can see, ffmpeg.ts starts out with video packets that do not have pts/dts. The audio packets that follow contain pts/dts. This repeats until the end. All video packets do not have pts/dts according to ffprobe output.

  However, out.ts starts with audio packets and alternate with video packets. Here, video packets also do not have pts/dts. The difference is that here there is one video packet between a series of audio packets. What happened to the rest of the video packets (ffmpeg.ts has 5 audio followed by 5 video).

  Obviously, I'm still learning and don't know way too much yet... Does anything jump out as obvious a problem to anyone ? I will greatly appreciate any info / suggestions but will continue to grind at it !!

• Not able to display first frame of mp4 file

  23 juin 2024, par Jatin Parmar

  I am learning OpenCV from YouTube, and I just created a very basic program in Python.

  


  import cv2 as cv

sources = cv.VideoCapture("test.mp4");

if not sources.isOpened():
    print("Failed to open video file");
else:
    print("video file opened successfully");

win_name = "test"
cv.namedWindow(win_name)

(has_input, frame) = sources.read()
if has_input:
    cv.imshow(win_name, frame[...,::-1])
    cv.waitKey(0)

sources.release()


  


  But when I run the program, I have the following errors : I have tried Googling it, but I didn't find any working solutions.

  


  [av1 @ 0x55e6dc8b0780] Missing Sequence Header.
[av1 @ 0x55e6dc8b0780] Missing Sequence Header.
[av1 @ 0x55e6dc8b0780] Missing Sequence Header.
[av1 @ 0x55e6dc8b0780] Missing Sequence Header.
[av1 @ 0x55e6dc8b0780] Missing Sequence Header.
[av1 @ 0x55e6dc8b0780] Missing Sequence Header.
[av1 @ 0x55e6dc8b0780] Missing Sequence Header.
[av1 @ 0x55e6dc8b0780] Missing Sequence Header.
[av1 @ 0x55e6dc8b0780] Missing Sequence Header.
video file opened successfully
[av1 @ 0x55e6dc97a7c0] Your platform doesn't suppport hardware accelerated AV1 decoding.
[av1 @ 0x55e6dc97a7c0] Failed to get pixel format.


  


  here is the link of video
https://drive.google.com/file/d/1TgY5O6pFLU3eEGsvmU0LoAw6_I8kGM6s/view?usp=sharing
I have no idea how to fix this.