LSMASHSource/LWLibavVideoSource

2024-08-04T04:35:20Z

JamesJohnston: Add note stating that FPS must be explicitly set when working with AVI files that have null/drop frames

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{{FilterCat|External_filters|Plugin_functions|Source_filters}}
This function uses [http://en.wikipedia.org/wiki/Libav#Video_codecs libavcodec] as a video decoder and libavformat as a demuxer.
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== [[Script variables|Syntax and Parameters]] ==
:{{Template:FuncDef|LWLibavVideoSource (string source, int "stream_index", int "threads", bool "cache", string "cachefile", int "seek_mode", int "seek_threshold", bool "dr", int "fpsnum", int "fpsden", bool "repeat", int "dominance", string "format", string "decoder", int "prefer_hw", int "ff_loglevel")}}
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::{{Par2|source|string| }}
:::The path of the source file; path can be omitted if the source file is in the same directory as the AviSynth script (*.avs).
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::{{Par2|stream_index|int|-1}}
:::The stream index to open in the source file. The value -1 means trying to get the video stream which has the largest resolution.
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::{{Par2|threads|int|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.
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::{{Par2|cache|bool|true}}
:::Create the index file (.lwi) to the same directory as the source file if set to true.
:::The index file avoids parsing all frames in the source file at the next or later access.
:::Parsing all frames is very important for frame accurate seek.
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::{{Par2|cachefile|string|source + ".lwi"}}
:::The filename of the index file (where the indexing data is saved).
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::{{Par2|seek_mode|int|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.
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::{{Par2|seek_threshold|int|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.
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::: * RAP is an abbreviation of random accessible point.
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::{{Par2|dr|bool|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.
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::{{Par2|fpsnum|int|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.
:::<br>
:::NOTE: You must explicitly set this if the source is an AVI file that contains null/drop frames that you would like to keep. For example, AVI files captured using VirtualDub commonly contain null/drop frames that were inserted during the capture process. Unless you provide this parameter, these null frames will be discarded, commonly resulting in loss of audio/video sync.
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::{{Par2|fpsden|int|1}}
:::Forced frame rate denominator.
:::See 'fpsnum' in details.
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::{{Par2|repeat|bool|false}}
:::Reconstruct frames by the flags specified in video stream and then treat all frames as interlaced if set to true and usable.
:::Note that this option is ignored when VFR->CFR conversion is enabled.
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::{{Par2|dominance|int|0}}
:::Which field, top or bottom, is displayed first.
::::*0 : Obey source flags
::::*1 : TFF i.e. Top -> Bottom
::::*2 : BFF i.e. Bottom -> Top
:::This option is enabled only if one or more of the following conditions is true.
::::- 'repeat' is set to true.
::::- There is a video frame consisting of two separated field coded pictures
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::{{Par2|format|string|""}}
:::Force specified output pixel format if 'format' is specified.
:::The following formats are available currently.
::::{| class="wikitable" border="1"; width="400px"
|-
!!width="200px"| Format
!!width="200px"| 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
|-
! colspan="2"| High bit depth is only supported in AviSynth+ and VapourSynth
|}
:::Note: direct rendering is not available at all if pixel format is forced.
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::{{Par2|decoder|string|""}}
:::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.
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::{{Par2|ff_loglevel|int|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.
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== Examples ==
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## LWLibavVideoSource with default settings:
'''LWLibavVideoSource'''("source.m2ts", stream_index=-1, threads=0,
\ cache=true, cachefile="source.lwi" seek_mode=0, seek_threshold=10,
\ dr=false, fpsnum=0, fpsden=1, repeat=false, dominance=0,
\ format="", decoder="", prefer_hw=0, ff_loglevel=0)
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## Decoding 10bit, YUV 4:2:0 source and converting to 8-bit.
'''LWLibavVideoSource'''(<''path''>, format="YUV420P10")
[[ConvertBits]](8, dither=0) ## '0' means on, '-1' means off
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LSMASHSource/LWLibavVideoSource