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linux:multimedia:movie [2017/07/19 10:52] niziak |
linux:multimedia:movie [2021/02/07 11:21] (current) niziak |
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| + | ====== Movie ====== | ||
| + | |||
| + | ===== Extract frames ===== | ||
| + | * Extract keyframes | ||
| + | * **-hide_banner** we are using this parameter to hide ffmpeg compilation information | ||
| + | * **-vsync vfr**: This is a parameter that tells the filter to use a variable bitrate video synchronization. If we do not use this parameter ffmpeg will fail to find only the keyframes and shoud extract other frames that can be not processed correctly. | ||
| + | <code bash>ffmpeg -i VIDEO0068.mp4 -vf "select=eq(pict_type\,I)" -vsync vfr thumb%04d.bmp -hide_banner</code> | ||
| + | * Extract one frame per second | ||
| + | <code bash>ffmpeg -i video.webm -vf fps=1 thumb%04d.jpg -hide_banner</code> | ||
| + | * Extract one frame per 10 seconds | ||
| + | <code bash>ffmpeg -i video.webm -vf fps=1/10 thumb%04d.jpg -hide_banner</code> | ||
| + | * Extract with different quality / to bmp | ||
| + | <code bash>ffmpeg -i video.webm -vf fps=1 -quality 90 thumb%04d.jpg -hide_banner</code> | ||
| + | <code bash>ffmpeg -i video.webm -vf fps=1 thumb%04d.bmp -hide_banner</code> | ||
| + | * Extract only one frame | ||
| + | <code bash>ffmpeg -i video.webm -ss 00:00:07.000 -vframes 1 thumb.jpg</code> | ||
| + | |||
| + | ===== Chroma subsampling ===== | ||
| + | [[https://en.wikipedia.org/wiki/Chroma_subsampling]] | ||
| + | {{ :linux:multimedia:sampling.jpg?200|}} | ||
| + | {{ :linux:multimedia:316-f6-chroma-subsampling-secondary_1.png?200|}} | ||
| + | * j:a:b - j - horizontal sampling reference (usually 4). **a** number of chroma samples (Cr, Cb) in the first row of **j** pixels. **b** number of changes of chroma samples between firs and second row of **j** pixels. | ||
| + | * 4:4:4 - (H265, H264) - no chroma subsampling - for every 4 pixels of luma, there are 4 pixels of colour | ||
| + | * 4:2:2 - 50Mbit - (H264) for every 4 pixels of luma, there are 2 pixels of colour. Keying can produce bad edges. | ||
| + | * 4:2:0 - 35MBit - (DVD, DV, JPEG, MPEG1, Blueray) - only alternatign lines are sampled for chroma. Chroma vertical resolution is halved. | ||
| + | |||
| + | |||
| + | ===== Stabilisation ===== | ||
| + | |||
| + | ==== To remove Little shaking in 1-pass ==== | ||
| + | |||
| + | <code bash>ffmpeg -threads 8 -i $1 -vf deshake -c:a copy -c:v utvideo yuv420p $1-deshake.mkv</code> | ||
| + | NOTE: No multithreading. | ||
| + | |||
| + | ==== To completely process shaky video in 2-pass| ==== | ||
| + | |||
| + | FFMpeg already contains plugins **vidstabdetect** and **vidstabtransform** [[http://public.hronopik.de/vid.stab/download.php]]. | ||
| + | But latest version (supports multithreading) can be downloaded as statically linked binary from: [[https://www.johnvansickle.com/ffmpeg/]] | ||
| + | |||
| + | <code bash> | ||
| + | ffmpeg -i $1 -vf vidstabdetect=shakiness=10:accuracy=15:result="tracefile.trf":show=1 -c:a copy -c:v utvideo ${PIX_FMT} ${OFILE}-vidstab1.mkv | ||
| + | ffmpeg -i $1 -vf vidstabtransform=input="tracefile.trf" -c:a copy -c:v utvideo ${PIX_FMT} ${OFILE}-vidstab2.mkv | ||
| + | </code> | ||
| + | NOTE: output from pass1 is also written as video to see motion vectors. | ||
| + | |||
| + | |||
| + | |||
| + | |||
| + | |||
| ===== Lossless ===== | ===== Lossless ===== | ||
| Line 4: | Line 53: | ||
| * Download for Windows: https://www.videohelp.com/software/Ut-Video-Codec-Suite | * Download for Windows: https://www.videohelp.com/software/Ut-Video-Codec-Suite | ||
| * Supported by ffmpeg | * Supported by ffmpeg | ||
| - | <code bash>ffmpeg -i $1 -vf deshake -c:a copy -c:v utvideo -pix_fmt yuv420p $1-deshake.mkv</code> | + | <code bash>ffmpeg -i $1 -vf deshake -c:a copy -c:v utvideo -pix_fmt yuv422p $1-deshake.mkv</code> |
| - | ===== mpeg2 ===== | + | Comparison of file size: |
| + | ^ pixfmt ^ huffyuv ^ utvideo ^ | ||
| + | | 444p | | 4104M | | ||
| + | | 422p | 4077M | 3204M | | ||
| + | | 420p | | 2556M | | ||
| + | |||
| + | The same video encoded using **utvideo** @422p is 78% of **huffyuv**. | ||
| + | ===== MPEG2 ===== | ||
| Highest quality (qscale 4-5 is far enough) | Highest quality (qscale 4-5 is far enough) | ||
| <code>-c:v mpeg2video -qscale:v 2</code> | <code>-c:v mpeg2video -qscale:v 2</code> | ||
| + | ==== DVD ==== | ||
| + | DVD's VOBS can be simply concatenated to one big file: | ||
| + | <code bash>cat ./VIDEO_TS/*.VOB | ffmpeg -i - <out_name>.<out_format></code> | ||
| + | |||
| + | <code bash> | ||
| + | #!/bin/bash -eu | ||
| + | |||
| + | VOBS="" | ||
| + | while read VOB; do | ||
| + | echo ${VOB} | ||
| + | if [ -n "${VOBS}" ]; then | ||
| + | VOBS="${VOBS}|" | ||
| + | fi | ||
| + | VOBS="${VOBS}${VOB}" | ||
| + | done < <(ls -1 *.VOB) | ||
| + | |||
| + | ffmpeg -i "concat:${VOBS}" -map 0:0 -map 0:1 -map 0:2 -c copy out.ts | ||
| + | </code> | ||
| + | More: [[https://newspaint.wordpress.com/2016/07/27/ripping-a-video-from-dvd-using-ffmpeg/]] | ||
| + | |||
| ===== H.264 params ===== | ===== H.264 params ===== | ||