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• ffmpeg - I want to concat multiple videos (front / rear) with overlay and one second delay

  12 mai 2024, par Andrej Florjančič

  I try to write bash script to concat front and rear video files with delay 1 second at start and overlay rear over front.

  


  I wrote the following bash script :

  


  # Define the output file
output_file="${VIDEO}/final_output_${choice}.mp4"

# Collect and sort the video files
front_files=( $(ls *_F.MP4 | sort) )
rear_files=( $(ls *_R.MP4 | sort) )

# Create a file to hold ffmpeg input commands and filter scripts
input_list="input_files.txt"
filter_script="filter_complex.txt"
inputs=""

# Clear the input list and filter script files
echo "" > "$input_list"
echo "" > "$filter_script"

# Number of files
num_files=${#front_files[@]}

# Iterate through the sorted files to build the filter script
for i in "${!front_files[@]}"; do
    echo "file '${front_files[$i]}'" >> "$input_list"
    echo "file '${rear_files[$i]}'" >> "$input_list"
    
    echo "[$((2*i)):v]trim=start=1,scale=1920:1080,setpts=PTS-STARTPTS[f_$i]; [$((2*i)):a]atrim=start=1,asetpts=PTS-STARTPTS[a_$i];" >> "$filter_script"
    echo "[$((2*i+1)):v]trim=start=1,scale=640:360,setpts=PTS-STARTPTS[r_$i];" >> "$filter_script"  # Rear video only
    echo "[f_$i][r_$i]overlay=x=(main_w-overlay_w-10):y=(main_h-overlay_h-10)[mix_$i];" >> "$filter_script"

    input+="[mix_$i][a_$i]"
done

# Concatenate all combined labels
echo "${input}concat=n=${#front_files[@]}:v=1:a=1[v][a]" >> "$filter_script"

# Run FFmpeg with filter script
ffmpeg -f concat -safe 0 -i "$input_list" \
    -filter_complex_script "$filter_script" \
    -map "[v]" -map "[a]" \
    -y "$output_file"


  


  This script generates two files input_list.txt :

  


  file '20200826_084407_F.MP4'
file '20200826_084407_R.MP4'
file '20200826_084708_F.MP4'
file '20200826_084708_R.MP4'
file '20200826_084910_F.MP4'
file '20200826_084910_R.MP4'


  


  filter_script.txt :

  


  [0:v]trim=start=1,scale=1920:1080,setpts=PTS-STARTPTS[f_0]; [0:a]atrim=start=1,asetpts=PTS-STARTPTS[a_0];
[1:v]trim=start=1,scale=640:360,setpts=PTS-STARTPTS[r_0];
[f_0][r_0]overlay=x=(main_w-overlay_w-10):y=(main_h-overlay_h-10)[mix_0];
[2:v]trim=start=1,scale=1920:1080,setpts=PTS-STARTPTS[f_1]; [2:a]atrim=start=1,asetpts=PTS-STARTPTS[a_1];
[3:v]trim=start=1,scale=640:360,setpts=PTS-STARTPTS[r_1];
[f_1][r_1]overlay=x=(main_w-overlay_w-10):y=(main_h-overlay_h-10)[mix_1];
[4:v]trim=start=1,scale=1920:1080,setpts=PTS-STARTPTS[f_2]; [4:a]atrim=start=1,asetpts=PTS-STARTPTS[a_2];
[5:v]trim=start=1,scale=640:360,setpts=PTS-STARTPTS[r_2];
[f_2][r_2]overlay=x=(main_w-overlay_w-10):y=(main_h-overlay_h-10)[mix_2];
[mix_0][a_0][mix_1][a_1][mix_2][a_2]concat=n=3:v=1:a=1[v][a]


  


  I'w got error :

  


  Input #0, concat, from 'input_files.txt':
  Duration: N/A, start: 0.000000, bitrate: 11973 kb/s
  Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080, 11877 kb/s, 30 fps, 30 tbr, 60k tbn, 60 tbc
    Metadata:
      creation_time   : 2020-08-26T08:47:07.000000Z
      handler_name    : VideoHandler
      vendor_id       : [0][0][0][0]
      encoder         : h264
  Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 32000 Hz, mono, fltp, 96 kb/s
    Metadata:
      creation_time   : 2020-08-26T08:47:07.000000Z
      handler_name    : SoundHandler
      vendor_id       : [0][0][0][0]
Invalid file index 1 in filtergraph description
[0:v]trim=start=1,scale=1920:1080,setpts=PTS-STARTPTS[f_0]; [0:a]atrim=start=1,asetpts=PTS-STARTPTS[a_0];
[1:v]trim=start=1,scale=640:360,setpts=PTS-STARTPTS[r_0];
[f_0][r_0]overlay=x=(main_w-overlay_w-10):y=(main_h-overlay_h-10)[mix_0];
[2:v]trim=start=1,scale=1920:1080,setpts=PTS-STARTPTS[f_1]; [2:a]atrim=start=1,asetpts=PTS-STARTPTS[a_1];
[3:v]trim=start=1,scale=640:360,setpts=PTS-STARTPTS[r_1];
[f_1][r_1]overlay=x=(main_w-overlay_w-10):y=(main_h-overlay_h-10)[mix_1];
[4:v]trim=start=1,scale=1920:1080,setpts=PTS-STARTPTS[f_2]; [4:a]atrim=start=1,asetpts=PTS-STARTPTS[a_2];
[5:v]trim=start=1,scale=640:360,setpts=PTS-STARTPTS[r_2];
[f_2][r_2]overlay=x=(main_w-overlay_w-10):y=(main_h-overlay_h-10)[mix_2];
[mix_0][a_0][mix_1][a_1][mix_2][a_2]concat=n=3:v=1:a=1[v][a]


  


  What am I doing wrong ?

  


• FFMpeg SDR and HDR side-by-side video encoding

  21 septembre 2023, par Famro Fexl

  I am attempting to create a side-by-side video with FFMpeg using the hstack filter.

  


  The SDR video is formatted as "AVC 8-bit YUV420p BT709 Gamma 2.4" and the HDR video is formatted as "HEVC 10-bit YUV420p10le BT2020 SMPTE2084 (with HDR10 metadata)".

  


  In order for the gamma and color space to match, I tried to convert the SDR video to an HDR format using filtering.

  


  Basically, I attempted to process the Rec.709 gamma 2.4 SDR content to Rec.2020 SMPTE2084 content so it could be combined and displayed in the same video. I'm not sure if the input pixel format mattered, at it appeared to be automatically transformed into the output pixel format. From everything I know, this should be theoretically possible.

  


  Here is my FFMpeg command for converting the SDR video into HDR :
ffmpeg -i input.mkv -filter_complex "colormatrix=bt709:bt2020" -color_primaries bt2020 -color_trc smpte2084 -c:v libx265 out.mkv

  


  The colorspace filter always returned the error [Parsed Colorspace_0 @ addr] Unsupported input primaries 2 (unknown), when using the filter_complex `colorspace=all=bt2020", so I was never able to use it.

  


  The HDR result had over-saturated reds in the color space and it was too dim in the gamma. I tried every gamma option available, but none of them matched the original SDR content.`

  


• avcodec/lpc : Avoid floating point division by 0

  28 mai 2021, par Michael Niedermayer

  avcodec/lpc : Avoid floating point division by 0
  Fixes : Ticket7996
  
  Fixes : CVE-2020-20445
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavcodec/lpc.c
  • [DH] libavcodec/lpc.h