LSMASHSource/LSMASHVideoSource

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LSMASHVideoSource uses libavcodec as a video decoder and L-SMASH as a demuxer. Recommended for MP4, MOV, ISO Base Media and its derived file formats. One advantage of LSMASHVideoSource is that it doesn't need to create an index file for its supported formats.

[edit] Syntax and Parameters

LSMASHVideoSource (string source, int "track", int "threads", int "seek_mode", int "seek_threshold", bool "dr", int "fpsnum", int "fpsden", string "format", string "decoder", int "prefer_hw", int "ff_loglevel)"


string  source =
The path of the source file; path can be omitted if the source file is in the same directory as the AviSynth script (*.avs).


int  track = 0
The track number to open in the source file.
The value 0 means trying to get the first detected video stream.


int  threads = 0
The number of threads to decode a stream by libavcodec.
The value 0 means the number of threads is determined automatically and then the maximum value will be up to 16.


int  seek_mode = 0
How to process when any error occurs during decoding a video frame.
  • 0 : Normal
This mode retries sequential decoding from the next closest RAP* up to 3 cycles when any decoding error occurs.
If all 3 trial failed, retry sequential decoding from the last RAP by ignoring trivial errors.
Still error occurs, then return the last returned frame.
  • 1 : Unsafe
This mode retries sequential decoding from the next closest RAP up to 3 cycles when any fatal decoding error occurs.
If all 3 trial failed, then return the last returned frame.
  • 2 : Aggressive
This mode returns the last returned frame when any fatal decoding error occurs.
* RAP is an abbreviation of random accessible point.


int  seek_threshold = 10
The threshold to decide whether a decoding starts from the closest RAP* to get the requested video frame or doesn't.
Let's say
the threshold is T,
and
you request to seek the M-th frame called f(M) from the N-th frame called f(N).
If M > N and M - N <= T, then
the decoder tries to get f(M) by decoding frames from f(N) sequentially.
If M < N or M - N > T, then
check the closest RAP at the first.
After the check, if the closest RAP is identical with the last RAP, do the same as the case M > N and M - N <= T.
Otherwise, the decoder tries to get f(M) by decoding frames from the frame which is the closest RAP sequentially.
* RAP is an abbreviation of random accessible point.


bool  dr = false
Try direct rendering from the video decoder if set to true.
The output resolution will be aligned to be mod16-width and mod32-height by assuming two vertical 16x16 macroblock.
For H.264 streams, in addition, 2 lines could be added because of the optimized chroma MC.


int  fpsnum = 0
Forced frame rate numerator.
If frame rate is set to a positive value, output frame rate is forced to the specified value by padding and/or dropping frames.
Otherwise, output frame rate is set to a computed average frame rate and the output process is performed by actual frame-by-frame.


int  fpsden = 1
Forced frame rate denominator.
See 'fpsnum' above.


string  format = ""
Force specified output pixel format if 'format' is specified.
The following formats are available currently.
Format Comments
"YUV420P8" YV12 / 4:2:0 planar
"YUV422P8" YV16 / 4:2:2 planar
"YUV444P8" YV24 / 4:4:4 planar
"YUV410P8" 4:1:0 planar
"YUV411P8" YV411 / 4:1:1 planar
"YUV420P9" 9-bit 4:2:0 planar
"YUV422P9" 9-bit 4:2:2 planar
"YUV444P9" 9-bit 4:4:4 planar
"YUV420P10" 10-bit 4:2:0 planar
"YUV422P10" 10-bit 4:2:2 planar
"YUV444P10" 10-bit 4:4:4 planar
"YUV420P12" 12-bit 4:2:0 planar
"YUV422P12" 12-bit 4:2:2 planar
"YUV444P12" 12-bit 4:4:4 planar
"YUV420P14" 14-bit 4:2:0 planar
"YUV422P14" 14-bit 4:2:2 planar
"YUV444P14" 14-bit 4:4:4 planar
"YUV420P16" 16-bit 4:2:0 planar
"YUV422P16" 16-bit 4:2:2 planar
"YUV444P16" 16-bit 4:4:4 planar
"YUVA420P8" 8-bit 4:2:0:4 planar with alpha channel
"YUVA422P8" 8-bit 4:2:2:4 planar with alpha channel
"YUVA444P8" 8-bit 4:4:4:4 planar with alpha channel
"YUVA420P10" 10-bit 4:2:0:4 planar with alpha channel
"YUVA422P10" 10-bit 4:2:2:4 planar with alpha channel
"YUVA444P10" 10-bit 4:4:4:4 planar with alpha channel
"YUVA420P12" 12-bit 4:2:0:4 planar with alpha channel
"YUVA422P12" 12-bit 4:2:0:4 planar with alpha channel
"YUVA444P12" 12-bit 4:4:4:4 planar with alpha channel
"YUVA420P16" 16-bit 4:2:0:4 planar with alpha channel
"YUVA422P16" 16-bit 4:2:2:4 planar with alpha channel
"YUVA420P16" 16-bit 4:4:4:4 planar with alpha channel
"Y8" Y8 / Grayscale
"Y10" 10-bit grayscale (ffmpeg only)
"Y12" 12-bit grayscale
"Y16" 16-bit grayscale
"YUY2" YUY2 / 4:2:2 interleaved
"RGB24" RGB24 / 4:4:4 interleaved
"RGB32" RGB32 / 4:4:4:4 interleaved
"RGB48" 16-bit RGB / 4:4:4 interleaved
"RGB64" 16-bit RGBA / 4:4:4:4 interleaved
"GBRP8" 8-bit RGB / 4:4:4 planar
"GBRP10" 10-bit RGB / 4:4:4 planar
"GBRP12" 12-bit RGB / 4:4:4 planar
"GBRP14" 14-bit RGB / 4:4:4 planar
"GBRP16" 16-bit RGB / 4:4:4 planar
"GBRAP8" 8-bit RGBA / 4:4:4:4 planar
"GBRAP10" 10-bit RGBA / 4:4:4:4 planar
"GBRAP12" 12-bit RGBA / 4:4:4:4 planar
"GBRAP14" 14-bit RGBA / 4:4:4:4 planar
"GBRAP16" 16-bit RGBA / 4:4:4:4 planar
High bit depth is only supported in AviSynth+ and VapourSynth
Note: direct rendering is not available at all if pixel format is forced.


string  decoder = ""
Names of preferred decoder candidates, separated by comma. For instance, if you prefer to use the 'h264_qsv' and 'mpeg2_qsv' decoders instead of the generally used 'h264' and 'mpeg2video' decoder, then specify as "h264_qsv,mpeg2_qsv". The evaluations are done in the written order and the first matched decoder, if any, is used.


int  prefer_hw = 0
Whether to prefer hardware accelerated decoder to software decoder.
Has no effect if 'decoder' is specified.
  • 0 : Use default software decoder.
  • 2 : Use Intel Quick Sync Video acceleration for supported codec, otherwise use default software decoder.
  • 3 : Try hardware decoder in the order of CUVID->QSV. If none is available then use default software decoder.


int  ff_loglevel = 0
Set the log level in FFmpeg.
  • 0 : AV_LOG_QUIET - Print no output.
  • 1 : AV_LOG_PANIC - Something went really wrong and we will crash now.
  • 2 : AV_LOG_FATAL - Something went wrong and recovery is not possible.
  • 3 : AV_LOG_ERROR - Something went wrong and cannot losslessly be recovered. However, not all future data is affected.
  • 4 : AV_LOG_WARNING - Something somehow does not look correct. This may or may not lead to problems.
  • 5 : AV_LOG_INFO - Standard information.
  • 6 : AV_LOG_VERBOSE - Detailed information.
  • 7 : AV_LOG_DEBUG - Stuff which is only useful for libav* developers.
  • 8 : AV_LOG_TRACE - Extremely verbose debugging, useful for libav* development.


[edit] Examples

## LSMASHVideoSource with default settings:
LSMASHVideoSource("source.mp4", track=0, threads=0, seek_mode=0, 
\                 seek_threshold=10, dr=false, fpsnum=0, fpsden=1, 
\                 format="", decoder="", prefer_hw=0, ff_loglevel=0)
## Decoding 10bit, YUV 4:2:0 source and converting to 8-bit.
LSMASHVideoSource(<path>, format="YUV420P10")
ConvertBits(8, dither=0) ## '0' means on, '-1' means off

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