diff options
author | diego <diego@b3059339-0415-0410-9bf9-f77b7e298cf2> | 2003-03-20 03:24:33 +0000 |
---|---|---|
committer | diego <diego@b3059339-0415-0410-9bf9-f77b7e298cf2> | 2003-03-20 03:24:33 +0000 |
commit | 25b01160bcb39fd156a060ecfc546b4641406da0 (patch) | |
tree | 95bb668716e0e7b0c84ec81c93746ca23a20f23b /DOCS/tech/libavc-options.txt | |
parent | af885100d37183720c8752a565a8164f0a76b4e1 (diff) | |
download | mpv-25b01160bcb39fd156a060ecfc546b4641406da0.tar.bz2 mpv-25b01160bcb39fd156a060ecfc546b4641406da0.tar.xz |
Finally merged libavc-option.txt into the man page.
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@9623 b3059339-0415-0410-9bf9-f77b7e298cf2
Diffstat (limited to 'DOCS/tech/libavc-options.txt')
-rw-r--r-- | DOCS/tech/libavc-options.txt | 432 |
1 files changed, 0 insertions, 432 deletions
diff --git a/DOCS/tech/libavc-options.txt b/DOCS/tech/libavc-options.txt deleted file mode 100644 index fcd3d84616..0000000000 --- a/DOCS/tech/libavc-options.txt +++ /dev/null @@ -1,432 +0,0 @@ -Description of what all those libavcodec options do ... -WARNING: I am no encoding expert so the recommendations might be bad ... -if you find any errors, missing stuff, ... send a patch or cvs commit if you -have an cvs account :) - -lavcopts: (encoder options) ---------------------------- - -vqmin 1-31 (minimum quantizer) for pass1/2 - 1 is not recommended (much larger file, little quality difference (if u are lucky) - and other weird things (if u are less lucky)) - weird things: msmpeg4, h263 will be very low quality - ratecontrol will be confused -> lower quality - some decoders will not be able to decode it - 2 is recommended for normal mpeg4/mpeg1video encoding (default) - 3 is recommended for h263(p)/msmpeg4 - the reason for 3 instead of 2 is that 2 could lead to overflows - (this will be fixed for h263(p) by changing the quanizer per MB in - the future, but msmpeg4 doesnt support that so it cant be fixed for - that) - -vqscale 1-31 quantizer for constant quantizer / constant quality encoding - 1 is not recommended (much larger file, little quality difference and - possible other weird things) - lower means better quality but larger files - see vqmin - -vqmax 1-31 (maximum quantizer) for pass1/2 - 31 default - 10-31 should be a sane range - -mbqmin 1-31 (minimum macroblock quantizer) for pass1/2 - 2 default - -mbqmax 1-31 (maximum macroblock quantizer) for pass1/2 - 31 default - -vqdiff 1-31 (maximum quantizer difference between I or P frames) for pass1/2 - 3 default - -vmax_b_frames 0-4 (maximum number of B frames between non B frames) - 0 no b frames (default) - 0-2 is a sane range for mpeg4 - -vme 0-5 (motion estimation) - 0 none (not recommanded, very lq) - 1 full (not recommanded, too slow) - 2 log (not recommanded, lq) - 3 phods (not recommanded, lq) - 4 EPZS (default) - 5 X1 (experimantal, might change from time to time or be just broken) - Note: 0-3 ignores the amount of bits spend currently, so dont complain - about low quality - -vhq (high quality mode) - encode each MB as in all modes and choose the best (this is slow but - better filesize/quality) - disabled by default - -v4mv - allow 4 MV per MB (little difference in filesize/quality) - disabled by default - -keyint 0-300 (maximum interval between keyframes) - keyframes are needed for seeking as seeking is only possible to a - keyframe but they need more space than non-keyframes so larger numbers here - mean slightly smaller files, but less precise seeking - 0 no keyframes - >300 is not recommended as the quality might be bad (depends upon - decoder, encoder and luck) - for strict mpeg1/2/4 compliance this would have to be <=132 - -vb_strategy 0-1 for pass 2 - 0 allways use the max number of B frames (default) - 1 avoid B frames in high motion scenes (this will cause bitrate - misprediction) - -vpass - 1 first pass - 2 second pass - (only need to specify if two-pass encoding is used) - Tip: u can try to use constant quantizer mode for pass1 (vqscale=<quantizer>) - for huffyuv: - pass 1 saves statistics - pass 2 encodes with a optimal huffman table based upon the pass 1 stats - -vbitrate (kbits per second) for pass1/2 - 800 is default - (if value is bigger then 16000 it is interpreted as bit not kbit!) - -vratetol (filesize tolerance in kbit) for pass1/2 - this is just an approximation, the real difference can be much smaller - or larger - 1000-100000 is a sane range - 8000 is default - -vrc_maxrate (maximum bitrate in kbit/sec) for pass1/2 -vrc_minrate (minimum bitrate in kbit/sec) for pass1/2 -vrc_buf_size (buffer size in kbit) for pass1/2 - this is for stuff like VCD - VCD: FIXME - SVCD: ... - DVD: ... - Note: vratetol should not be too large during the 2.pass or there might - be problems if vrc_(min|max)rate is used - -vb_qfactor (-31.0-31.0) for pass1/2 - 1.25 is default -vi_qfactor (-31.0-31.0) for pass1/2 - 0.8 is default -vb_qoffset (-31.0-31.0) for pass1/2 - 1.25 is default -vi_qoffset (-31.0-31.0) for pass1/2 - 0.0 is default - if v{b|i}_qfactor > 0 - I/B-Frame quantizer = P-Frame quantizer * v{b|i}_qfactor + v{b|i}_qoffset - else - do normal ratecontrol (dont lock to next P frame quantizer) and - set q= -q * v{b|i}_qfactor + v{b|i}_qoffset - tip: to do constant quantizer encoding with different quantizers for - I/P and B frames you can use: - vqmin=<ip_quant>:vqmax=<ip_quant>:vb_qfactor=<b_quant/ip_quant> - -vqblur (0.0-1.0) quantizer blur (pass1) - 0.0 qblur disabled - 0.5 is the default - 1.0 average the quantizer over all previous frames - larger values will average the quantizer more over time so that it will - be changed slower -vqblur (0.0-99.0) quantizer blur (pass2) - gaussian blur (gaussian blur cant be done during pass 1 as the future quantizers arent known) - 0.5 is the default - larger values will average the quantizer more over time so that it will - be changed slower - -vqcomp quantizer compression (for pass1/2) - depends upon vrc_eq - -vrc_eq the main ratecontrol equation (for pass1/2) - 1 constant bitrate - tex constant quality - 1+(tex/avgTex-1)*qComp approximately the equation of the old ratecontrol code - tex^qComp with qcomp 0.5 or something like that (default) - - infix operators: +,-,*,/,^ - variables: - tex texture complexity - iTex,pTex intra, non intra texture complexity - avgTex average texture complexity - avgIITex average intra texture complexity in I frames - avgPITex average intra texture complexity in P frames - avgPPTex average non intra texture complexity in P frames - avgBPTex average non intra texture complexity in B frames - mv bits used for MVs - fCode maximum length of MV in log2 scale - iCount number of intra MBs / number of MBs - var spatial complexity - mcVar temporal complexity - qComp qcomp from the command line - isI, isP, isB is 1 if picture type is I/P/B else 0 - Pi,E see ur favorite math book - - functions: - max(a,b),min(a,b) maximum / minimum - gt(a,b) is 1 if a>b, 0 otherwise - lt(a,b) is 1 if a<b, 0 otherwise - eq(a,b) is 1 if a==b,0 otherwise - sin,cos,tan,sinh,cosh,tanh,exp,log,abs - -vrc_override user specified quality for specific parts (ending credits ...) (for pass1/2) - <start-frame>,<end-frame>,<quality>[/<start-frame>,<end-frame>,<quality>[/...]] - quality 2..31 -> quantizer - quality -500..0 -> quality correcture in % - -vrc_init_cplx (0-1000) initial complexity for pass1 - -vqsquish (0 or 1) for pass1/2 how to keep the quantizer between qmin & qmax - 0 use cliping - 1 use a nice differentiable function (default) - -vlelim (-1000-1000) single coefficient elimination threshold for luminance - 0 disabled (default) - -4 (JVT recommendation) - negative values will allso consider the dc coefficient - should be at least -4 or lower for encoding at quant=1 - -vcelim (-1000-1000) single coefficient elimination threshold for chrominance - 0 disabled (default) - 7 (JVT recommendation) - negative values will allso consider the dc coefficient - should be at least -4 or lower for encoding at quant=1 - -vstrict (-1,0,1) strict standard compliance - 0 (default) - 1 only recommended if you want to feed the output into the mpeg4 reference - decoder - -1 allows nonstandard YV12 huffyuv encoding (20% smaller files, but - cant be played back by the official huffyuv codec) - -vdpart data partitioning - adds 2 byte per video packet - each videopacket will be encoded in 3 seperate partitions: - 1. MVs (=movement) - 2. DC coefficients (=low res picture) - 3. AC coefficients (=details) - the MV & DC are most important, loosing them looks far worse than - loosing the AC and the 1. & 2. partition (MV&DC) are far smaller than - the 3. partition (AC) -> errors will hit the AC partition much more - often than the MV&DC -> the picture will look better with partitioning - than without, as without partitining an error will trash AC/DC/MV - equally - improves error-resistance when transfering over unreliable channels (eg. - streaming over the internet) - -vpsize (0-10000) video packet size - 0 disabled (default) - 100-1000 good choice - improves error-resistance (see vdpart for more info) - -gray grayscale only encoding (a bit faster than with color ...) - -vfdct (0-99) dct algorithm - 0 automatically select a good one (default) - 1 fast integer - 2 accurate integer - 3 mmx - 4 mlib - -idct (0-99) idct algorithm - 0 automatically select a good one (default) - 1 jpeg reference integer - 2 simple - 3 simplemmx - 4 libmpeg2mmx (inaccurate, DONT USE for encoding with keyint >100) - 5 ps2 - 6 mlib - 7 arm - note: all these IDCTs do pass the IEEE1180 tests AFAIK - -lumi_mask (0.0-1.0) luminance masking - 0.0 disabled (default) - 0.0-0.3 should be a sane range - warning: be carefull, too large values can cause disasterous things - warning2: large values might look good on some monitors but may look horrible - on other monitors - -dark_mask (0.0-1.0) darkness masking - 0.0 disabled (default) - 0.0-0.3 should be a sane range - warning: be carefull, too large values can cause disasterous things - warning2: large values might look good on some monitors but may look horrible - on other monitors / TV / TFT - -tcplx_mask (0.0-1.0) temporal complexity masking - 0.0 disabled (default) - -scplx_mask (0.0-1.0) spatial complexity masking - 0.0 disabled (default) - 0.0-0.5 should be a sane range - larger values help against blockiness, if no deblocking filter is used - for decoding - Tip: crop any black borders completly away as they will reduce the quality - of the MBs there, this is true if scplx_mask isnt used at all too - -naq normalize adaptive quantization (experimental) - when using adaptive quantization (*_mask), the average per-MB quantizer - may no longer match the requested frame-level quantizer. using naq will - attempt to adjust the per-MB quantizers to maintain the proper average. - -ildct use interlaced dct - -format - YV12 (default) - 422P (for huffyuv) - -pred (for huffyuv) - 0 left prediction - 1 plane/gradient prediction - 2 median prediction - -qpel use quarter pel motion compensation - Tip: this seems only usefull for high bitrate encodings - -precmp comparission function for motion estimation pre pass -cmp comparission function for full pel motion estimation -subcmp comparission function for sub pel motion estimation -mbcmp comparission function for macroblock decission - 0 SAD (sum of absolute differences) (default) - 1 SSE (sum of squared errors) - 2 SATD (sum of absolute hadamard transformed differences) - 3 DCT (sum of absolute dct transformed differences) - 4 PSNR (sum of the squared quantization errors) (dont use, low quality) - 5 BIT (number of bits needed for the block) - 6 RD (rate distoration optimal, slow) - 7 ZERO (0) - +256 (use chroma too, doesnt work (correctly) with b frames currently) - Tip: SAD is fast, SATD is good, SSE is something in between - Tip2: when using SATD/DCT/BIT/RD for full pel search then a - larger diamond something like dia=2 or dia=4 might improve - quality, but only for some videos - Note: mbcmp is only used if hq mode is disabled - -predia (-99 - 6) diamond type & size for motion estimation pre pass -dia (-99 - 6) diamond type & size for motion estimation - ... - -3 shape adaptive diamond with size 3 - -2 shape adaptive diamond with size 2 - -1 experimental - 1 normal size=1 diamond (default) =EPZS type diamond - 0 - 000 - 0 - 2 normal size=2 diamond - 0 - 000 - 00000 - 000 - 0 - ... - Tip: the shape adaptive stuff seems to be faster at the same quality - Note: the sizes of the normal diamonds and shape adaptive ones dont - have the same meaning - -trell trellis quantization - this will find the optimal encoding for each 8x8 block - trellis quantization is quite simple a optimal quantization in the - PSNR vs bitrate sense (assuming that there would be no rounding errors introduced - by the IDCT, which is obviously not the case) it simply finds a block for the minimum of - error + lambda*bits - lambda is a qp dependant constant - bits is the amount of bits needed to encode the block - error is simple the sum of squared errors of the quantization - -last_pred (0-99) amount of motion predictors from the previous frame - 0 (default) - a -> will use 2a+1 x 2a+1 MB square of MV predictors from the previous frame - -preme (0-2) Motion estimation pre-pass - 0 disabled - 1 only after I frames (default) - 2 allways - -subq (1-8) subpel refinement quality (for qpel) - 8 (default) - Note: this has a significant effect on the speed - -psnr will print the psnr for the whole video after encoding and store the per frame psnr - in a file with name like "psnr_012345.log" - -aic advanced intra prediction (H.263+ only) - Note: vqmin should be 8 or larger - -umv unlimited MVs (H.263+ only) - allow encoding of abritary long MVs - - -lavdopts: (decoder options) ---------------------------- - -ec error concealment - 1 use strong deblock filter for damaged MBs - 2 iterative MV search (slow) - 3 all (default) - Note: just add the ones u want to enable - -er error resilience - 0 disabled - 1 carefull (should work with broken encoders) - 2 normal (default) (works with compliant encoders) - 3 agressive (more checks but might cause problems even for valid bitstreams) - 4 very agressive - -bug manual workaround encoder bugs (autodetection isnt foolproof for these) - 0 nothing - 1 autodetect bugs (default) - 2 for msmpeg4v3 some old lavc generated msmpeg4v3 files (no autodetect) - 4 for mpeg4 xvid interlacing bug (autodetected if fourcc==XVIX) - 8 for mpeg4 UMP4 (autodetected if fourcc==UMP4) - 16for mpeg4 padding bug (autodetected) - 32for mpeg4 illegal vlc bug (autodetected per fourcc) - 64for mpeg4 XVID&DIVX qpel bug (autodetected per fourcc/ver) - 128 mpeg4 old standard qpel (autodetected per fourcc/ver) - 256 mpeg4 another qpel bug (autodetected per fourcc/ver) - 512 mpeg4 direct-qpel-blocksize bug(autodetected per fourcc/ver) - 1024 mpeg4 edge padding bug (autodetected per fourcc/ver) - Note: just add the ones u want to enable - -gray grayscale only decoding (a bit faster than with color ...) - -idct see lavcopts - note: the decoding quality is highest if the same idct algorithm is used - for decoding as for encoding, this is often not the most accurate though - - -Notes: 1. lavc will strictly follow the quantizer limits vqmin, vqmax, vqdiff - even if it violates the bitrate / bitrate tolerance - 2. changing some options between pass1 & 2 can reduce the quality - -FAQ: Q: Why is the filesize much too small? - A: Try to increase vqmin=2 or 1 (be carefull with 1, it could cause - strange things to happen). - Q: What provides better error recovery while keeping the filesize low? - Should I use data partitioning or increase the number of video packets? - A: Data partitioning is better in this case. - -Glossary: -MB Macroblock (16x16 luminance and 8x8 chrominance samples) -MV Motion vector -ME Motion estimation -MC Motion compensation -RC Rate control -DCT Discrete Cosine Transform -IDCT Inverse Discrete Cosine Transform -DC The coefficient of the constant term in the DCT (avg value of block) -JVT Joint Video Team Standard -- http://www.itu.int/ITU-T/news/jvtpro.html -PSNR peak signal to noise ratio - -Examples: -mencoder foobar.avi -lavcopts vcodec=mpeg4:vhq:keyint=300:vqscale=2 -o new-foobar.avi -mplayer foobar.avi -lavdopts bug=1 - -Links: -short intro to mpeg coding: -http://www.eecs.umich.edu/~amarathe/mpeg.html -longer intro to jpeg/mpeg coding: -http://www.cs.sfu.ca/undergrad/CourseMaterials/CMPT479/material/notes/Chap4/Chap4.2/Chap4.2.html -ftp://ftp.tek.com/mbd/manuals/video_audio/25W_11418_4.pdf - --- -Written 2002 by Michael Niedermayer and reviewed by Felix Buenemann. -Check the MPlayer documentation for contact-addresses. - |