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• Missing piece between libjpeg-turbo & h264 ffmpeg C/C++

  15 octobre 2022, par Nelstaar

  On the left side I have a buffer with decoded pixels that I can get in two formats :

  


  RGB interleaved/packed where bytes in buffer are R0G0B0R1G1B1....

  


  or

  


  YUV444 interleaved/packed where bytes in buffer are Y0U0V0Y1U1V1...

  


  (JCS_RGB or JCS_YCbCr in jpeglib.h)

  


  (Please note that I use libjpeg-turbo because I need to decompress a cropped region of the image. (jpeg_crop_scanline()))

  


  On the right side I have x264 codec via ffmpeg that support only planar pixel formats :

  


  yuv420p, yuvj420p, yuv422p, yuvj422p, yuv444p, yuvj444p, nv12, nv16, nv21, yuv420p10le, yuv422p10le, yuv444p10le, nv20le

  


  yuv444p where bytes in buffer are Y0Y1Y2...U0U1...V0V1...

  


  according to ffmpeg -h encoder=libx264

  


  I have some ideas already :

  


  

  • Decompress Jpeg to RBG888 in buffer 1 then libswscale to yuv420p in buffer 2 and encoding. (copy)

  


  • Decompress Jpeg to YUV444 interleaved in buffer 1 then SSSE3 magic in buffer 1 to yuv444p and encoding. (no copy)

  


  • or else.

  


  


  What would be the most effective fastest way ?

  


  I which to avoid buffer copy.

  


  Movie have the same width & height than Jpegs.

  


• FFMPEG : Creating video using drawtext along with word wrap and padding

  11 octobre 2022, par Chaitanya Sai

  I'm working to create a video from text with drawtext filter. Output video i can see the text is overflowing instead of coming in new line.

  



  Is there any way i can archive word wrapping and also set the internal padding to video ?

  



  Below is the snippet I'm using to generate video from text

  



  ffmpeg.exe -f lavfi -i color=c=white:s=640x480:d=5.396 -vf "[in] drawtext=fontfile=font.ttf:fontsize=20:fontcolor=black:x=0+0*print(tw):y=0+0*print(th):text='this is new whiteboard te':enable='between(t,6.634,6.818)',drawtext=fontfile=font.ttf:fontsize=20:fontcolor=black:x=0+0*print(tw):y=0+0*print(th):text='this is new whiteboard testing':enable='between(t,0.0,2.032)',drawtext=fontfile=font.ttf:fontsize=20:fontcolor=black:x=0+0*print(tw):y=0+0*print(th):text='this is new whiteboard testing no padding and the text is overflowing from the video frame check this  need to acheve word wrapping':enable='between(t,2.032,5.396)'"[out] -c:v libx264 -t 30 -crf 30 ../output.mp4


  



  Output looks like this


  


• Subtitle word scaling with ASS file causing line shifting

  23 avril 2024, par Barrard

  I'm trying to make my subtitles scale one word at a time, but I'm running into an issue with the whole line shifting.
Is there a way I can scale a word, and make the other words not move sue to the scale effect ?
Here is the ASS File

  


  [Script Info]
ScriptType: v4.00+
PlayResX: 384
PlayResY: 288
ScaledBorderAndShadow: yes
[V4+ Styles]
Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, 
BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, 
BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
Style: Default,Arial,18,&H00FFFFFF,&H00FFFFFF,&H00000000,&HFF000000,-1,0,0,0,100,100,0,0,3,1,0.6,5,10,10,10,0
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:0.00,0:00:1.00,Default,,0,0,0,,{\an5\pos(192,144)\alpha&HFF&}And so my fellow Americans,
Dialogue: 0,0:00:0.00,0:00:02.50,Default,,0,0,0,,{\an5\pos(192,144)\fscx90\fscy90\t(0,2500,\fscx120\fscy120)}And{\fscx100\fscy100} so my fellow Americans,
Dialogue: 0,0:00:2.50,0:00:05.00,Default,,0,0,0,,{\an5\pos(192,144)\fscx120\fscy120\t(0,2500,\fscx100\fscy100)}And{\fscx100\fscy100} so my fellow Americans,


  


  this shows the video output.
https://youtube.com/shorts/d4VaoWqTMtQ?feature=share

  


  Thanks in advanced.