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NAMEtranscode - LINUX video stream processing toolSYNOPSIStranscode -i name [-o name] [-y vmod,amod] [-w vbitrate [ ,vkeyframes [ ,vcrispness ] ]] [-a atrack [ ,vtrack ]] [-b abitrate [ ,is_vbr [ ,quality [ ,mode ] ] ]] [-M demuxer_mode] [-F codec_string] [other options] QUICK SUMMARYtranscode supports a huge range of options, as described in detail in further section. Only one option is mandatory: -i name, for supplying the input main (video) source. All other options are discretionary and they can be skipped. Most commonly needed options are -o, -y, -w, -a, -b, -M, -F and a fair number of transcode session needs a little more than those. See section below for full description of all transcode options. To inspect the properties of a module, such as their parameters or the help text, use the ´tcmodinfo´ tool.DESCRIPTIONtranscode is a linux text-console utility for video stream processing, running on a platform that supports shared libraries and threads.It supports a huge range of options, as described in detail in further section. Only one option is mandatory: -i name, for supplying the input main (video) source. All other options are discretionary and they can be skipped. Most commonly needed options are -o, -y, -w, -a, -b, -M, -F and a fair number of transcode session needs a little more than those. See section below for full description of all transcode options. Decoding and encoding is done by loading modules that are responsible for feeding transcode with raw video/audio streams (import modules) and encoding the frames (export modules). It supports elementary video and audio frame transformations, including de-interlacing or fast resizing of video frames and loading of external filters. A number of modules are included to enable import of DVDs on-the-fly, MPEG elementary (ES) or program streams (VOB), MPEG video, Digital Video (DV), YUV4MPEG streams, NuppelVideo file format, AVI based codecs and raw or compressed (pass-through) video frames and export modules for writing DivX;-), XviD, DivX 4.xx/5.xx or uncompressed AVI and raw files with MPEG, AC3 (pass-through) or PCM audio. Additional export modules to write single frames (PPM) or YUV4MPEG streams are available, as well as an interface import module to the avifile library. It´s modular concept is intended to provide flexibility and easy user extensibility to include other video/audio codecs or filetypes. A set of tools is included to demux (tcdemux), extract (tcextract) and decode (tcdecode) the sources into raw video/audio streams for import, probing (tcprobe) and scanning (tcscan) your sources and to enable post-processing of AVI files, fixing AVI file header information (avifix), merging multiple files (avimerge), splitting large AVI files (avisplit) to fit on a CD and avisync to correct AV-offsyncs. OPTIONS-Ause AC3 as internal audio codec [off]. Only pass-through
supported.
-B n[,m[,M]] resize to height-n*M rows
[,width-m*M] columns [off,32]. M must be one of 8, 16 or
32. It makes no difference which M you use. You might look at the fast
flag of the -Z option if you don not want to calculate n and
m yourself.
-C mode enable anti-aliasing mode (1-3) [off].
1 de-interlace effects only
2 resize effects only
3 process full frame (slow)
-D num sync video start with audio frame num [0].
-E r[,b[,c]] audio output samplerate [Hz], bits per sample and
channels [as input]. The option "-J resample" must be provided for
export modules not capable of re-sampling. Samplerate and bits per sample can
be specified as 0 to mean "same as input"; this allows converting
from stereo to mono while leaving the other parameters alone (-E 0,0,1).
-F codec_string encoder parameter strings [module dependent]. The -F
parameter has different meanings for different export modules. Those meanings
are documented in transcode_export(1) manual page.
-G val Gamma correction (0.0-10.0) [off]. A value of 1.0 does
not change anything. A value lower than 1.0 will make the picture
"brighter", a value above 1.0 will make it "darker".
-H n auto-probe n MB of source (0=disable) default [1].
Use a higher value than the default to detect all subtitles in the VOB.
-I mode enable de-interlacing mode (1-5) [off].
1 "interpolate scanlines" linear interpolation (takes the average of the surronding even rows to determine the odd rows), and copies the even rows as is. 2 "handled by encoder" tells the encoding code to handle the fact that the frames are interlaced. Most codecs do not handle this. 3 "zoom to full frame" drops to to half size, then zooms out. This can cause excessive blurring which is not always unwanted. On the other hand results are quite good. 4 "drop field / half height" drop every other field and keep half height. 5 "interpolate scanlines / blend frames" linear blend (similar to -vop pp=lb in mplayer) this, like linear blend calculates the odd rows as the average of the surrounding even rows, and also calculates the even rows as an average of the original even rows and also calculates the even rows as an average of the original odd rows and averages the calculated and original rows. Something like avg (avg(row1,row3), avg(row2, row4)) -J filter1[,filter2[,...]] apply external filter plugins [off]. The avalaible import
modules and their options are documented into the transcode_filter(1)
manual page. Note: You can specify more than one -J argument. The order
of filter arguments specify in which order the filters are applied. Note also,
for transcode internally it makes no difference whether you do "-J
filter1 -J filter2" or "-J filter1,filter2". Use
´tcmodinfo -i NAME´ to get more information about the
filter_NAME. Not all filters support this but most of them do. Some of
the filter plugins have additional documentation in the docs/ directory.
-L n seek to VOB stream offset nx2kB default [0]. This
option is usually calculated automatically when giving --nav_seek and
-c.
-K enable black/white by removing colors mode (grayscale)
[off]. Please note this does not necessarily lead to a smaller image / better
compression. For YUV mode, this is done by emptying the chroma planes, for RGB
mode a weightend grayscale value is computed.
-M mode demuxer PES AV sync modes (0-4) [1].
Overview The demuxer takes care that the right video frames go
together with the right audio frame. This can sometimes be a complex task and
transcode tries to aid you as much as possible. WARNING: It does make a
difference if you (the user) specifies a demuxer to use or if transcode resp.
tcprobe(1) chooses the one which it thinks is right for your material. This is
done on purpose to avoid mystic side-effects. So think twice, wether you
specify a demuxer or let transcode choose one or you might end up with an
off-sync result.
0 Pass-through. Do not mess with the stream, switch off any
synchronization/demuxing process.
1 PTS only (default). Synchronize video and audio by
inspecting PTS/DTS time stamps of audio and video. Preferred mode for PAL VOB
streams and DVDs.
2 NTSC VOB stream synchronization feature. This mode
generates synchronization information for transcode by analyzing the frame
display time.
3 (like -M 1): sync AV at initial PTS, but invokes
"-D/--av_fine_ms" options internally based on "tcprobe"
PTS analysis. PTS stands for Presentation Time Stamp.
4 (like -M 2): initial PTS / enforce frame rate, with
additional frame rate enforcement (for NTSC).
-N format select export format. Default is mp3 for audio, and
module-dependant format for video. This option has two different behaviours
and accepts two different set of options, as side-effect of ongoing export
module transition. For old-style modules (current default, as found in 1.0.x
series), argument is audio format ID has hexadecimal value: see below for a
list of recognized IDs. Default id, so default format for audio exported
track, is MP3 (0x55). If you are using, the transcode´s the new-style
encode/multiplex modules (still under development, see the encode and
multiplex directories), argument is a comma-separated pair of export format
names. Use tcmodinfo tool to check out what new-style export module support
what formats.
Available format for old-style behaviour are: 0x1 PCM uncompressed audio
0x50 MPEG layer-2 aka MP2
0x55 MPEG layer-3 aka MP3. Also have a look at --lame_preset
if you intend to do VBR audio.
0x2000 AC3 audio
0xfffe OGG/Vorbis audio
-O skip flushing of buffers at encoder stop [off, do
flushing at each stop].
-P flag pass-through flag (0=off|1=V|2=A|3=A+V) [0]. Pass-through
for flag != 1 is broken and not a trivial thing to fix.
You can pass-through DV video, AVI files and MPEG2 video. When doing MPEG2 pass-through (together with the -y raw module), you can give a requantization factor by using -w (for example -w 1.5), this will make the MPEG2 stream smaller. The pass-through mode is useful for reconstruction of a broken index of an AVI file. The -x ffmpeg import-module analyzes the compressed bitstream and can detect a keyframe for DIV3, MPEG4 (DivX, XviD, ..) and other formats. It then sets an internal flag which the export module will respect when writing the frame out. -Q n[,m] encoding[,decoding] quality (0=fastest-5=best)
[5,5].
-R n[,f1[,f2]] enable multi-pass encoding (0-3) [0,divx4.log,pcm.log].
0 Constant bitrate (CBR) encoding. [default] The codec tries to achieve constant bitrate output. This
means, each encoded frame is mostly the same size. This type of encoding can
help in maintaining constant filling of hardware buffer on set top players or
smooth streaming over networks. By the way, Constant bitrate is often obtained
sacrifying quality during high motion scenes.
1 Variable bitrate encoding: First pass. In this mode, the codec analyses the complete sequence in
order to collect data that can improve the distribution of bits in a second
VBR pass. The collected data is written to second sub argument (default:
divx4.log). This data is codec dependant and cannot be used across codecs. It
is strongly advised to use the same codec settings for the VBR analysis pass
and the VBR encoding pass if you want predictable results.
The video output of the first pass is not of much use and can grow very large. It´s a good idea to not save the video output to a file but directly to /dev/null. Usually the bitrate is ignored during first pass. Disabling audio export makes sense too, so use -y codec,null. It is not recommended to disable the audio import because transcode might drop video frames to keep audio and video in sync. This is not possible when the audio import is disabled. It may lead to the fact that the codec will see a different sequence of frames which effectively renders the log file invalid. 2 Variable bitrate encoding: Second pass. The first pass allowed the codec collecting data about
the complete sequence. During the second pass, the codec will use that data in
order to find an efficient bit distribution that respects both the desired
bitrate and the natural bitrate curve shape. This ensures a good compromise
between quality and desired bitrate.
Make sure you activate both sound and video encoding during this pass. 3 Constant quantizer encoding. The quantizer is the "compression level" of the
picture. The lower the quantizer is, the higher is the quality of the picture.
This mode can help in making sure the sequence is encoded at constant quality,
but no prediction can be made on the final bitrate. When using this mode, the
-w option changes its meaning, it now takes the quantizer ranging from
1 to 31. Note that constant quantizer encoding is not supported with some
codecs (notably mpeg1/2/4 with -y ffmpeg).
-S unit[,s1-s2] process program stream unit[,s1-s2] sequences [0,all].
This option is a bit redundant to --psu*. This option lets you specify which
units you want to have decoded or skipped. At a program stream unit boundary,
all (internal) mpeg timers are reset to 0. tcprobe will tell you how many
units are in one file.
-T t[,c[,a]] select DVD title[,chapter[,angle]] [1,1,1]. Only a single
chapter is transcoded. Use -T 1,-1 to trancode all chapters in a row.
You can even specify chapter ranges.
-U base process DVD in chapter mode to base-ch%02d.avi
[off].
-V format select video layout / colour space for internal
processing. Possible values for this options are: yuv420p (default), yuv422p,
rgb24
yuv420p is default because it is most codecs´ internal format so there is no need for conversions. Some modules may not support it though: use rgb in that case. rgb24 is the old (pre-0.6.13) transcode internal format. Most codecs do not support this format natively and have to convert it to/from YUV first, so only use this option if you´re really sure or you want to use a module that doesn´t support YUV. yuv422p is an experimental feature and a developers playground. Not many import, export and filter modules support this colorspace. A 4:2:2 colorspace offers much more quality than the consumer oriented 4:2:0 colorspaces like I420/YV12. Most equipment in film and video post-production uses YUV422. YUV422 doubles the precision for chroma (color difference) information in the image. All internal transformations are supported in YUV422 mode (clipping, flipping, zooming, etc). -W n,m[,nav_file] autosplit and process part n of m (VOB
only) [off]
-X n[,m,[M]] resize to height+n*M rows
[,width+m*M] columns [off,32]. M must be one of 8, 16 or 32. It
makes no difference which M you use. You might look at the fast flag of
the -Z option if you do not want to calculate n and m
yourself.
-Y top[,left[,bottom[,right]]] select (encoder) frame region by clipping border.
Negative values add a border [off].
-Z widthxheight[,fast|interlaced] resize to width columns, height rows with
filtering [off,notfast,notinterlaced]. If fast is given, transcode will
calculate the parameters for -X and/or -B. The file fast
can only be used when the import and export geometry of an image is a multiple
of 8.
In fast mode, a faster but less precise resizing algorithm will be used resulting in a slightly less good quality. Beside this (small) drawback, it is worth a try. If interlaced is given, transcode will assume the frame is interlaced when resizing, and resize each field independently. This will give better results on interlaced video, but is incompatible with fast mode. Also, the height (both old and new) must be a multiple of 4. It is also possible to omit width OR height. In this case, transcode will calculate the missing value using the import aspect ratio. The new value will be aligned to be a multiple of 8. Using an additional fast or interlaced is also possible. Examples (assume input is a 16:9 coded file at 720x576): -Z 576x328 uses filtered zoom. -Z 576x328,fast uses fast zoom. -Z 576x,fast guess 328 and do fast zoom. -Z x328,interlaced guess 576 and do interlaced zoom. -a ach[,vch] extract audio[,video] track for encoding.
-b b[,v,[q,[m]]] audio encoder bitrate kBits/s[,vbr[,quality[,mode]]]
[128,0,5,0]
The mode parameter specifies which modus lame should use for encoding. Available modes are: 0 Joint Stereo (default)
1 Full stereo
2 Mono
-c f1-f2[,f3-f4[, ... ] ] encode only frames f1-f2 [and f3-f4].
Default is to encode all available frames. Use this and you´ll get
statistics about remaining encoding time. The f[N] parameters may also
be timecodes in the HH:MM:SS.FRAME format. Example:
-c 500-0:5:01,:10:20-1:18:02.1 Note that transcode starts counting frames at 0 and excludes the last frame specified. That means that "-c 0-100" will encoded 100 frames starting at frame 0 up to frame 99 -d swap bytes in audio stream [off]. In most cases, DVD PCM
audio tracks require swapping of audio bytes
-e r[,b[,c]] PCM audio stream parameter. Sample rate [Hz], bits per
sample and number of channels [48000,16,2]. Normally this is
autodetected.
-f rate[,frc] import video frame rate[,frc] [25.000,0]. If frc
(frame rate code) is specified, transcode will calculate the precise frames
per second internally. Valid values for frc are:
1 23.976 (24000/1001.0)
2 24
3 25
4 29.970 (30000/1001.0)
5 30
6 50
7 59.940 (2 * 29.970)
8 60
9 1
10 5
11 10
12 12
13 15
-g WidthxHeight video stream frame size [720x576].
-h print out usage information.
-i name input file/directory/device/mountpoint/host name, default
is [/dev/zero].
-j top[,left[,bottom[,right]]] select frame region by clipping border. Negative values
add a border [off].
-k swap red/blue (Cb/Cr) in video frame [off]. Use if people
have blue faces.
-l mirror video frame [off].
-m file write audio stream to separate file [off].
-n 0xnn import audio format id [0x2000]. Normally, this is
autodetected.
-o file output file name, default is [/dev/null].
-p file read audio stream from separate file [off].
-q debuglevel possible values for debuglevel:
0 QUIET
1 INFO
2 DEBUG
4 STATS
8 WATCH
16 FLIST
32 VIDCORE
64 SYNC
128 COUNTER
256 PRIVATE
-r n[,m] reduce video height/width by n[,m] [off]. Example:
-r 2 will rescale the framesize of a 720x576 file to 360x288.
-s gain,[center,[front,[rear]]] increase volume of audio stream by
gain,[center,front,rear] default [off,1,1,1].
-t n,base split output to base%03d.avi with n frames
[off].
-u m[,n] use m framebuffer[,n threads] for AV
processing [10,1].
-v print version.
-w b[,k[,c]] encoder bitrate[,keyframes[,crispness]] [(6000 for MPEG
1/2, 1800 for others),250,100].
--video_max_bitrate b Use b as maximal bitrate (kbps) when encoding
variable bitrate streams.
-x vmod[,amod] video[,audio] import modules [auto,auto]. If omitted,
transcode will probefor appropriate import modules. The avalaible import
modules and their options are documented into the transcode_import(1)
manual page.
-y vmod[,amod[,mmod]] video[,audio[,multiplex]] export modules [null]. If
omitted, transcode will encode to the null module. If a multiplex
module is given, transcode will use the new-style encode/multiplex modules
(still under development, see the encode and multiplex directories); if no
multiplex module is given, the traditional export modules will be used. The
avalaible export, encoder and multiplexor modules and their options are
documented into the transcode_export(1) manual page.
--accel type enforce experimental IA32 acceleration for type
[autodetect]. type may be one of
C No acceleration
ia32asm plain x86 assembly
mmx MMX instruction set
3dnow 3DNow! instruction set
sse SSE instruction set
sse2 SSE2 instruction set
--avi_limit N split/rotate output AVI file after N MB [2048].
--avi_comments F Read AVI header comments from file F [off]. The
AVI file format supports so-called tomb-stone data. It can be used to write
annotations into the AVI file.
See the file docs/avi_comments.txt for a sample input file with all tags. When the file is read, empty lines and lines starting with ´#´ are ignored. The syntax is: "TAG<space>STRING". The order of the tags does not matter. If a tag has no string following it, it is ignored. That means, you can use the file docs/avi_comments.txt as input and only fill out the fields you want. A very simple example is: ----------------snip---------------- INAM My 1st Birthday ISBJ My first steps! IART My proud family ----------------snip---------------- --zoom_filter string use filter string for video resampling -Z
[Lanczos3] The following filters are available:
Bell Box Lanczos3 (default) Mitchell Hermite B_spline Triangle --cluster_percentage use percentage mode for cluster encoding -W>
[off]
--cluster_chunks a-b process chunk range instead of selected chunk [off]
--export_asr C set export aspect ratio code C [as input] Valid
codes for C are:
1 1:1
2 4:3
3 16:9
4 2.21:1
--export_prof S WARNING: this option will be renamed as
--export_profile in future releases.
Select an export profile {vcd, svcd, xvcd, dvd} [-pal|-ntsc|-secam]. Default is no profile. If you set this meta option to one of the values below, transcode will adjust some internal paramaters as well as geometry and clipping. If no export modules are specified, mpeg2enc for video and mp2enc for audio are used when compiled with mjpegtools support. Valid values for S are e.g. vcd, vcd-pal, vcd-ntsc, svcd, svcd-pal, ... xvcd profile is equal to svcd except that it allows for up to 9000 Kbps video bitrate (default is 5000) and arbitrary audio samplerate. When one of the above is used, transcode will calculate the needed clipping and resizing values for you based on the import and export aspect ratio. This is especially handy if you want to encode a 16:9 DVD into a 4:3 SVCD for example. Transcode internally then sets --pre_clip to add the black bars ("letterboxing"). If you use "vcd" instead of "vcd-pal" or "vcd-ntsc", transcode will make an educated guess if PAL or NTSC vcd is wanted. The same is true for the other profiles. When the input file has no aspect ratio information at all, transcode guesses it based on the import frame sizes. You can set the import aspect ratio by giving --import_asr CODE. Examples (assume input is a 16:9 coded file at 720x576 (PAL)): --export_prof svcd clip top/bot -96; resizes to 480x576 --export_prof vcd-ntsc clip top/bot -96; resizes to 352x240 transcode -i vob/ --export_prof svcd -Z fast -o test transcode -i vob/ --export_prof dvd -y ffmpeg -o test -m test.ac3 tcmplex -m d -i test.m2v -p test.ac3 -o test.mpg --export_par C[,N] set export pixel aspect ratio to C[,N]. To
encode anamorphic material, transcode can encode the target pixel aspect ratio
into the file. This is NOT the actual aspect ratio of the image, but only the
amount by which every single pixel is stretched when played with an aspect
ratio aware application, like mplayer.
To encode at non standard aspect ratios, set both C and N. E.g. to make every pixel twice as high as it´s wide (e.g. to scale back to normal size after deinterlacing by dropping every second line). If C and N are specified, the value set for C does give the pixel aspect ratio of the width and N the one for the height. If only C is specified, the table below applies. Valid codes for C are 1 1:1 No stretching
2 12:11 5:4 image to 4:3 (ex: 720x576 -> 768x576)
3 10:11 3:2 image to 4:3 (ex: 720x480 -> 640x480)
4 16:11 5:4 image to 16:9 (ex: 720x576 ->
1024x576)
5 40:33 3:2 image to 16:9 (ex: 720x480 -> 872x480)
--import_asr C set import aspect ratio code C [autoprobed]
Valid codes for C are 1 1:1
2 4:3
3 16:9
4 2.21:1
--keep_asr try to keep aspect ratio (only with -Z) [off]
The --keep_asr options changes the meaning of -Z. It tries to fit the video into a framesize specified by -Z by keeping the original aspect ratio. +----------------+ +---480-----+ | | | black | |720x306 = 2.35:1| -> -Z 480x480 --keep_asr ->|-----------4 | | | 480x204 8 +----------------+ |-----------0 | black | +-----------+ --mplayer_probe use external mplayer binary to probe stream, reset
default import modules as mplayer ones [off]. Default is to use internal
probing code. Using this option without mplayer import modules (-x
mplayer) can lead to unpredictable and possibly wrong results.
--quantizers min,max set encoder min/max quantizer. This is meaningfull only
for video codecs of MPEG family. For other kind of codecs, this options is
harmless. [2,31]
--divx_rc p,rp,rr divx encoder rate control parameter [2000,10,20]
--divx_vbv_prof N divx5 encoder VBV profile (0=free-5=hiqhq) [3]. Sets a
predefined profile for the Video Bitrate Verifier. If N is set to zero,
no profile is applied and the user specified values from --divx_vbv are
used.
Valid profiles 0 Free/No profile ( Use supplied values )
1 Handheld ( 320, 16, 3072 )
2 Portable ( 1920, 64, 12288 )
3 Home Theatre ( 10000, 192, 36864 )
4 High Definition ( 20000, 384, 73728 )
--divx_vbv br,sz,oc divx5 encoder VBV params (bitrate,size,occup.)
[10000,192,36864] These parameters are normally set through the profile
parameter --divx_vbv_prof. Do not mess with theses value unless you are
absolutely sure of what you are doing. Transcode internally multiplicates
vbv_bitrate with 400, vbv_size with 16384 and vbv_occupancy with 64 to ensure
the supplied values are multiples of what the encoder library wants.
--export_fps rate[,frc] set export frame rate (and code) [as input].Valid values
for frc are
frc rate 1 23.976 (24000/1001.0)
2 24
3 25
4 29.970 (30000/1001.0)
5 30
6 50
7 59.940 (2 * 29.970)
8 60
9 1
10 5
11 10
12 12
13 15
--export_frc F set export frame rate code F [as input].
Obsolete, use --export_fps 0,F
--hard_fps disable smooth dropping (for variable fps clips) [off].
See /docs/framerate.txt for more information.
--pulldown set MPEG 3:2 pulldown flags on export [off]
--antialias_para w,b center pixel weight, xy-bias [0.333,0.500]
--no_audio_adjust disable internal audio frame sample adjustment
[off]
--no_bitreservoir disable lame bitreservoir for MP3 encoding [off]
--config_dir dir Assume config files are in this dir. This only
affects the -y ffmpeg and -y xvid4 modules. It gives the path where the
modules search for their configuration.
--lame_preset name[,fast] use lame preset with name [off]. Lame features
some built-in presets. Those presets are designed to provide the highest
possible quality. They have for the most part been subject to and tuned via
rigorous listening tests to verify and achieve this objective. These are
continually updated to coincide with the latest developments that occur and as
a result should provide you with nearly the best quality currently possible
from LAME. Any of those VBR presets can also be used in fast mode, using the
new vbr algorithm. This mode is faster, but its quality could be a little
lower. To enable the fast mode, append ",fast"
<N kbps> Using this preset will usually give you good quality at a
specified bitrate. Depending on the bitrate entered, this preset will
determine the optimal settings for that particular situation. While this
approach works, it is not nearly as flexible as VBR, and usually will not
reach the same quality level as VBR at higher bitrates. ABR.
medium This preset should provide near transparency to most
people on most music. The resulting bitrate should be in the 150-180kbps
range, according to music complexity. VBR.
standard This preset should generally be transparent to most
people on most music and is already quite high in quality. The resulting
bitrate should be in the 170-210kbps range, according to music complexity.
VBR.
extreme If you have extremely good hearing and similar equipment,
this preset will provide slightly higher quality than the "standard"
mode. The resulting bitrate should be in the 200-240kbps range, according to
music complexity. VBR.
insane This preset will usually be overkill for most people and
most situations, but if you must have the absolute highest quality with no
regard to filesize, this is the way to go. This preset is the highest preset
quality available. 320kbps CBR.
(taken from http://www.mp3dev.org/mp3/doc/html/presets.html)[1] --av_fine_ms t AV fine-tuning shift t in millisecs [autodetect]
also see -D.
--nav_seek file use VOB or AVI navigation file [off]. Generate a nav file
with tcdemux -W >nav_log for VOB files or with aviindex(1) for AVI
files.
--psu_mode process VOB in PSU, -o is a filemask incl. %d [off]. PSU
means Program Stream Unit and this mode is useful for (mostly) NTSC DVDs which
have several program stream units.
--psu_chunks a-b process only selected units a-b for PSU mode
[all]
--no_split encode to single file in chapter/psu/directory mode
[off]. If you don´t give this option, you´ll end up with several
files in one of the above mentioned modes. It is still possible to merge them
with avimerge(1).
--multi_input (EXPERIMENTAL) enable multiple input mode: intelligently join input files in import. The inputs can be expressed using standard POSIX globbing. While theorically all input modules are supported, it is safe to use this only when dealing with constant-sized audio (PCM) and intra-frame only video codecs (es: MJPEG). To be safe, use this mode with im, ffmpeg and raw import modules. --pre_clip t[,l[,b[,r]]] select initial frame region by clipping border
[off]
--post_clip t[,l[,b[,r]]] select final frame region by clipping border [off]
--a52_drc_off disable liba52 dynamic range compression [enabled]. If
you dont specify this option, liba52 will provide the default behaviour, which
is to apply the full dynamic range compression as specified in the A/52
stream. This basically makes the loud sounds softer, and the soft sounds
louder, so you can more easily listen to the stream in a noisy environment
without disturbing anyone.
If you let it enabled this this will totally disable the dynamic range compression and provide a playback more adapted to a movie theater or a listening room. --a52_demux demux AC3/A52 to separate channels [off]
--a52_dolby_off disable liba52 dolby surround [enabled]. Selects whether
the output is plain stereo (if the option is set) or if it is Dolby Pro Logic
- also called Dolby surround or 3:1 - downmix (if the option is not
used).
--log_no_color disable colored log messages. By default transcode use
colors in log messages in order to easily distinguish message classes. That
behaviour can be problematic if output of transcode is a file or a pipe, so
this option came handful.
--dir_mode base process directory contents to base-%03d.avi [off]
--frame_interval N select only every Nth frame to be exported
[1]
--encode_fields C enable field based encoding (if supported) [off]. This
option takes an argument if given to denote the order of fields. If the option
is not given, it defaults to progressive (do not assume the picture is
interlaced)
Valid codes for C are: p progressive (default)
t top-field first
b bottom-field first
--dv_yuy2_mode, --dv_yv12_mode Indicates that libdv decodes Digital Video frames in YUY2
(packed) or YV12 (planar) mode, respectively. Normally transcode figures out
the correct mode automatically, but if you try to transcode PAL DV files and
the results look strange, try one of these options.
--write_pid file write pid of signal thread to file [off]. Enables
you to terminate transcode cleanly by sending a SIGINT (2) to the pid in
file. Please note file will be overwritten. Usage example
$ transcode ... --write_pid /tmp/transcode.pid & $ kill -2 `cat /tmp/transcode.pid` --nice N set niceness to N [off]. The option --nice which
renices transcode to the given positive or negative value. -10 sets a high
priority; +10 a low priority. This might be useful for cluster mode.
--progress_meter N select type of progress meter [1]. Selects the type of
progress message printed by transcode:
0 no progress meter
1 standard progress meter
2 raw progress data (written to standard output)
Scripts that need progress data should use type 2, since the format of type 1 is subject to change without notice. --progress_rate N print progress every N frames [1]. Controls how
frequently the status message is printed (every N frames).
--socket FILE Open a socket to accept commands while running. See
tcmodinfo(1) and /docs/filter-socket.txt for more information about the
protocol.
ENVIRONMENTTRANSCODE_LOG_NO_COLORif set, forces the colored logging off for all the tools
of transcode suite.
NOTES*Most source material parameter are auto-detected.
* Clipping region options are expanded symmetrically.
Examples:
-j 80 will be expanded to -j 80,0,80,0 -j 80,8 will be expanded to -j 80,8,80,8 -j 80,8,10 will be expanded to -j 80,8,10,8 * maximum image size is 1920x1088.
* The video frame operations ordering is fixed: "-j -I
-X -B -Z -Y -r -z -l -k -K -G -C" (executed from left to right).
* Shrinking the image with ´-B´ is not
possible if the image width/height is not a multiple of 8, 16 or 32.
* Expanding the image with ´-X´ is not
possible if the image width/height is not a multiple of 8, 16 or 32.
* The final frame width/height should be a multiple of 8.
(to avoid encoding problems with some codecs)
1. Reducing the video height/width by 2,4,8 Option
´-r factor´ can be used to shrink the video image by a constant
factor, this factor can be 2,4 or 8.
2. Clipping and changing the aspect ratio transcode
uses 3 steps to produce the input image for the export modules
1. Clipping of the input image.
2. Changing the aspect ratio of the 1) output.
3. Clipping of the 2) output.
* Bits per pixel (bits/pixel) is a value transcode calculates and prints when starting up. It is mainly useful when encoding to MPEG4 (xvid, divx, etc). You´ll see line like [transcode] V: bits/pixel | 0.237 Simplified said, bits/pixel quantifies how good an encode will be. Although this value depends heavily on the used input material, as a general rule of thump it can be said that values greater or close to 0.2 will result in good encodes, encodes with values less than 0.15 will have noticeable artifacts. Bits per pixel depends on the resolution, bitrate and frames per second. If you have a low value ( < 0.15), you might want to raise the bitrate or encode at a lower resolution. The exact formula is bitrate*1000 bpp = ------------------ width*height*fps * AC3 / Multiple channels When you do import an audio stream which has more then two audio channels - this is usually the case for AC3 audio - transcode will automagically downmix to two channels (stereo). You´ll see line like [transcode] A: downmix | 5 channels -> 2 channels This is done, because most encoders and audio filters can not handle more than 2 channels correctly. The PCM internal representation does not support more than two channels, audio will be downmixed to stereo No downmix will happen, if you use AC3 as the internal audio codec or use audio pass-through. EXAMPLESThe following command will read it´s input from the DVD drive (I assume /dev/dvd is a symbolic link to the actual DVD device) and produce a splitted divx4 movie according to the chapter information on the DVD medium. The output files will be named my_movie-ch00.avi, my_movie-ch01.avi ...transcode -i /dev/dvd/ -x dvd -j 16,0 -B 5,0 -Y 40,8 -s 4.47 -U my_movie -y xvid -w 1618 Option -j 16,0 will be expanded to -j 16,0,16,0 and results in 16 rows from the top and the bottom of the image to be cut off. This may be usefull if the source consists of black top and bottom bars. Option -B 5,0 tells transcode to shrink the resulting image by 5*32=160 rows in height. Option -Y 40,8 will be expanded to -Y 40,8,40,8 and tells transcode to ... Option -s 4.47 tells transcode to increase audio volume by a factor 4.47. Option -U my_movie tells transcode to operate in chapter mode and produce output to files named my_movie-ch00.avi, my_movie-ch01.avi.... You can either merge the files afterwards with avimerge or add the option --no_split to the command line. Option -y xvid tells transcode to use the export module export_xvid.so which in turn uses the XviD encoder to encode the video. Option -w 1618 tells transcode to set the encoder bitrate to 1618 which is lower than the default of 1800 and results in smaller files with the loss of visual quality. Lets assume that you have an NTSC DVD (720x480) and you want to make an NTSC-SVCD The frame size of the DVD movie is 720x480 @ 16:9. For
the purpose of frame resizing, the width 720 is not relavant (that is, it will
not be used in the following reasoning). It is not needed because the original
frame size is really defined by the frame height and aspect ratio. The _final
result_ should be 640x480, encoded as 480x480 @ 4:3 (the height 480 multiplied
by the aspect ratio 4:3 gives the width 640). This same frame size (640x480)
can also be encoded as 640x360 @ 16:9 (the height 360 by the aspect ratio 16:9
gives the width 640).
As the _original video_ has aspect ratio 16:9, first we resize to 640x360, keeping that aspect ratio. But the aspect ratio has to be changed to 4:3. To find the frame size in the new aspect ratio the height 360 is multiplied by the new aspect ratio, giving the width 480. This is accomplished with the transcode options "--export_asr 2 -Z 480x360,fast". To avoid stretching the video height in this change (because the new aspect ratio is less than the original), black borders should be added at the top and bottom of the video, bringing the frame to the desired 480x480 @ 4:3 size. The transcode option for this is "-Y -60,0,-60,0". If for some reason (maybe a subtitle filter) the black borders (of height 60 each) should be added before resizing the frame and changing the aspect ratio to 4:3. One reason for that would be the need of running a _pre_ filter after adding the black borders. Then the options "-j" or "--pre_clip" can be used instead of "-Y". In this case the black border height has to be recalculated by applying the aspect ratio 4:3 to the value alreadyfound: 60 * (4/3) = 80. The transcode options "-j -80,0,-80,0" or "--pre_clip -80,0,-80,0" are then used instead of "-Y -60,0,-60,0", and "-Z 480x360,fast" is replaced by "-Z 480x480,fast". AUTHORSWritten by Thomas Oestreich <ostreich@theorie.physik.uni-goettingen.de>, Tilmann Bitterberg and the Transcode-TeamSee the AUTHORS file for details. SEE ALSOtranscode_export(1) , transcode_filter(1) , transcode_import(1) , avifix(1) , avisync(1) , avimerge(1) , avisplit(1) , tcprobe(1) , tcscan(1) , tccat(1) , tcdemux(1) , tcextract(1) , tcdecode(1) , tcmodinfo(1) , tcxmlcheck(1) , transcode(1)WWWFrequently asked questions (FAQ) at http://www.transcoding.org/cgi-bin/transcode?Transcode_FAQ [1] Example transcode sessions at http://www.transcoding.org/cgi-bin/transcode?Command_Examples [1]BUGSYes, there are bugs in transcode! Do your part and report them immediately.For details, see http://www.transcoding.org/cgi-bin/transcode?Reporting_Problems [1] NOTES
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