From c09948b6dcbb223cd3bff706e4b03499814a9d7e Mon Sep 17 00:00:00 2001 From: Fabrice Bellard Date: Mon, 2 Jun 2003 20:13:30 +0000 Subject: [PATCH] autogeneration of html files Originally committed as revision 1927 to svn://svn.ffmpeg.org/ffmpeg/trunk --- doc/Makefile | 5 +- doc/faq.html | 148 ------- doc/ffmpeg-doc.html | 910 ------------------------------------------ doc/ffserver-doc.html | 312 --------------- doc/hooks.html | 90 ----- 5 files changed, 4 insertions(+), 1461 deletions(-) delete mode 100644 doc/faq.html delete mode 100644 doc/ffmpeg-doc.html delete mode 100644 doc/ffserver-doc.html delete mode 100644 doc/hooks.html diff --git a/doc/Makefile b/doc/Makefile index 034d4921b4..ac344908e8 100644 --- a/doc/Makefile +++ b/doc/Makefile @@ -1,4 +1,7 @@ all: ffmpeg-doc.html faq.html ffserver-doc.html hooks.html -%.html: %.texi +%.html: %.texi Makefile texi2html -monolithic -number $< + +clean: + rm -f *.html diff --git a/doc/faq.html b/doc/faq.html deleted file mode 100644 index 2d5b95b89b..0000000000 --- a/doc/faq.html +++ /dev/null @@ -1,148 +0,0 @@ - - - - -FFmpeg FAQ - - -

FFmpeg FAQ

-

-

-

Table of Contents

- -

- -

-FFmpeg FAQ - - - - -

1. General Problems

- - - -

1.1 ffserver doesn't not work.

- -

-ffmpeg development is now concentrated on the codec and format -handling. New developments broke ffserver, so don't expect it to work -correctly. It is planned to fix it ASAP. - - - - -

1.2 I cannot read this file although this format seems to be suppored by ffmpeg.

- -

-Even if ffmpeg can read the file format, it may not support all its -codecs. Please consult the supported codec list in the ffmpeg -documentation. - - - - -

1.3 I get audio/video synchro problems when grabbing.

- -

-Currently, the grabbing stuff does not handle synchronisation -correctly. You are free to correct it. It is planned to fix it ASAP. - - - - -

1.4 How do I encode jpegs to another format ?

- -

-If the jpegs are named img1.jpg, img2.jpg, img3.jpg,..., use: - - - -

-  ffmpeg -i img%d.jpg /tmp/a.mpg
-
- -

-`%d' is replaced by the image number. - - -

-`img%03d.jpg' generates `img001.jpg', `img002.jpg', etc... - - -

-The same system is used for the other image formats. - - - - -

1.5 FFmpeg does not support codec XXX. Can you include a Windows DLL loader to support it ?

- -

-No. FFmpeg only supports open source codecs. Windows DLLs are not -portable, bloated and often slow. - - - - -

1.6 How can I read from the standard input or write to the standard output ?

- -

-Use `-' as filename. - - - - -

2. Development

- - - -

2.1 Can you support my C compiler XXX ?

- -

-No. Only GCC is supported. GCC is ported on most systems available and I -don't see the need to pollute the source code with #ifdefs -related to the compiler. - - - - -

2.2 I want to use ffmpeg or libavcodec under Windows. Can you support my proprietary C compiler XXX ?

- -

-No. Use mingw-gcc available at http://www.mingw.org/ to -compile the code. It generates object files fully compatible with other -windows compilers. - - - - -

2.3 Can you add automake, libtool or autoconf support ?

- -

-No. These tools are too blowted and they complicate the build. Moreover, -since only `gcc' is supported they would add little advantages in -terms of portability. - - -

-This document was generated on 28 December 2002 using -texi2html 1.56k. - - diff --git a/doc/ffmpeg-doc.html b/doc/ffmpeg-doc.html deleted file mode 100644 index faffc41be2..0000000000 --- a/doc/ffmpeg-doc.html +++ /dev/null @@ -1,910 +0,0 @@ - - - - -FFmpeg Documentation - - -

FFmpeg Documentation

-

-

-

Table of Contents

- -

- -

-FFmpeg Documentation - - - - -

1. Introduction

- -

-FFmpeg is a very fast video and audio converter. It can also grab from -a live audio/video source. - -The command line interface is designed to be intuitive, in the sense -that ffmpeg tries to figure out all the parameters, when -possible. You have usually to give only the target bitrate you want. - - -

-FFmpeg can also convert from any sample rate to any other, and resize -video on the fly with a high quality polyphase filter. - - - - -

2. Quick Start

- - - -

2.1 Video and Audio grabbing

- -

- FFmpeg can use a video4linux compatible video source and any Open Sound - System audio source: - -

-  ffmpeg /tmp/out.mpg 
-
- -

- Note that you must activate the right video source and channel before - launching ffmpeg. You can use any TV viewer such as xawtv - (http://bytesex.org/xawtv/) by Gerd Knorr which I find very - good. You must also set correctly the audio recording levels with a - standard mixer. - - - - -

2.2 Video and Audio file format conversion

- -

-* ffmpeg can use any supported file format and protocol as input: - - -

-Examples: - - -

-* You can input from YUV files: - - - -

-  ffmpeg -i /tmp/test%d.Y /tmp/out.mpg 
-
- -

- It will use the files: - -

-       /tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
-       /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
-
- -

- The Y files use twice the resolution of the U and V files. They are - raw files, without header. They can be generated by all decent video - decoders. You must specify the size of the image with the '-s' option - if ffmpeg cannot guess it. - - -

-* You can input from a RAW YUV420P file: - - - -

-  ffmpeg -i /tmp/test.yuv /tmp/out.avi
-
- -

- The RAW YUV420P is a file containing RAW YUV planar, for each frame first - come the Y plane followed by U and V planes, which are half vertical and - horizontal resolution. - - -

-* You can output to a RAW YUV420P file: - - - -

-  ffmpeg -i mydivx.avi -o hugefile.yuv
-
- -

-* You can set several input files and output files: - - - -

-  ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
-
- -

- Convert the audio file a.wav and the raw yuv video file a.yuv - to mpeg file a.mpg - - -

-* You can also do audio and video conversions at the same time: - - - -

-  ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
-
- -

- Convert the sample rate of a.wav to 22050 Hz and encode it to MPEG audio. - - -

-* You can encode to several formats at the same time and define a - mapping from input stream to output streams: - - - -

-  ffmpeg -i /tmp/a.wav -ab 64 /tmp/a.mp2 -ab 128 /tmp/b.mp2 -map 0:0 -map 0:0
-
- -

- Convert a.wav to a.mp2 at 64 kbits and b.mp2 at 128 kbits. '-map - file:index' specify which input stream is used for each output - stream, in the order of the definition of output streams. - - -

-* You can transcode decrypted VOBs - - - -

-  ffmpeg -i snatch_1.vob -f avi -vcodec mpeg4 -b 800 -g 300 -bf 2 -acodec mp3 -ab 128 snatch.avi
-
- -

- This is a typical DVD ripper example, input from a VOB file, output - to an AVI file with MPEG-4 video and MP3 audio, note that in this - command we use B frames so the MPEG-4 stream is DivX5 compatible, GOP - size is 300 that means an INTRA frame every 10 seconds for 29.97 fps - input video. Also the audio stream is MP3 encoded so you need LAME - support which is enabled using --enable-mp3lame when - configuring. The mapping is particularly useful for DVD transcoding - to get the desired audio language. - - -

- NOTE: to see the supported input formats, use ffmpeg -formats. - - - - -

3. Invocation

- - - -

3.1 Syntax

- -

- The generic syntax is: - - - -

-  ffmpeg [[options][-i input_file]]... {[options] output_file}...
-
- -

- If no input file is given, audio/video grabbing is done. - - -

- As a general rule, options are applied to the next specified - file. For example, if you give the '-b 64' option, it sets the video - bitrate of the next file. Format option may be needed for raw input - files. - - -

- By default, ffmpeg tries to convert as losslessly as possible: it - uses the same audio and video parameter for the outputs as the one - specified for the inputs. - - - - -

3.2 Main options

- -
- -
`-L' -
-show license -
`-h' -
- show help -
`-formats' -
-show available formats, codecs, protocols, ... -
`-f fmt' -
-force format -
`-i filename' -
-input file name - -
`-y' -
-overwrite output files - -
`-t duration' -
-set the recording time in seconds. hh:mm:ss[.xxx] syntax is also -supported. - -
`-title string' -
-set the title - -
`-author string' -
-set the author - -
`-copyright string' -
-set the copyright - -
`-comment string' -
-set the comment - -
`-b bitrate' -
-set video bitrate (in kbit/s) -
- - - -

3.3 Video Options

- -
- -
`-s size' -
-set frame size [160x128] -
`-r fps' -
-set frame rate [25] -
`-b bitrate' -
-set the video bitrate in kbit/s [200] -
`-vn' -
-disable video recording [no] -
`-bt tolerance' -
-set video bitrate tolerance (in kbit/s) -
`-sameq' -
-use same video quality as source (implies VBR) - -
`-pass n' -
-select the pass number (1 or 2). It is useful to do two pass encoding. The statistics of the video are recorded in the first pass and the video at the exact requested bit rate is generated in the second pass. - -
`-passlogfile file' -
-select two pass log file name - -
- - - -

3.4 Audio Options

- -
- -
`-ab bitrate' -
-set audio bitrate (in kbit/s) -
`-ar freq' -
- set the audio sampling freq [44100] -
`-ab bitrate' -
- set the audio bitrate in kbit/s [64] -
`-ac channels' -
- set the number of audio channels [1] -
`-an' -
- disable audio recording [no] -
- - - -

3.5 Advanced options

- -
- -
`-map file:stream' -
-set input stream mapping -
`-g gop_size' -
-set the group of picture size -
`-intra' -
-use only intra frames -
`-qscale q' -
-use fixed video quantiser scale (VBR) -
`-qmin q' -
-min video quantiser scale (VBR) -
`-qmax q' -
-max video quantiser scale (VBR) -
`-qdiff q' -
-max difference between the quantiser scale (VBR) -
`-qblur blur' -
-video quantiser scale blur (VBR) -
`-qcomp compression' -
-video quantiser scale compression (VBR) -
`-vd device' -
-set video device -
`-vcodec codec' -
-force video codec -
`-me method' -
-set motion estimation method -
`-bf frames' -
-use 'frames' B frames (only MPEG-4) -
`-hq' -
-activate high quality settings -
`-4mv' -
-use four motion vector by macroblock (only MPEG-4) -
`-ad device' -
-set audio device -
`-acodec codec' -
-force audio codec -
`-deinterlace' -
-deinterlace pictures -
`-benchmark' -
-add timings for benchmarking -
`-hex' -
-dump each input packet -
`-psnr' -
-calculate PSNR of compressed frames -
`-vstats' -
-dump video coding statistics to file -
- - - -

3.6 Protocols

- -

-The filename can be `-' to read from the standard input or to write -to the standard output. - - -

-ffmpeg handles also many protocols specified with the URL syntax. - - -

- Use 'ffmpeg -formats' to have a list of the supported protocols. - - -

- The protocol http: is currently used only to communicate with - ffserver (see the ffserver documentation). When ffmpeg will be a - video player it will also be used for streaming :-) - - - - -

4. Tips

- - - - - - -

5. Supported File Formats and Codecs

- -

-You can use the -formats option to have an exhaustive list. - - - - -

5.1 File Formats

- -

-FFmpeg supports the following file formats through the libavformat -library: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Supported File Format Encoding Decoding Comments
MPEG audio X X
MPEG1 systems X X muxed audio and video -
MPEG2 PS X X also known as VOB file -
MPEG2 TS X also known as DVB Transport Stream -
ASF X X
AVI X X
WAV X X
Macromedia Flash X X Only embedded audio is decoded -
Real Audio and Video X X
Raw AC3 X X
Raw MJPEG X X
Raw MPEG video X X
Raw PCM8/16 bits, mulaw/Alaw X X
SUN AU format X X
Quicktime X
MPEG4 X MPEG4 is a variant of Quicktime -
Raw MPEG4 video X X
DV X Only the video track is decoded. -
- -

-X means that the encoding (resp. decoding) is supported. - - - - -

5.2 Image Formats

- -

-FFmpeg can read and write images for each frame of a video sequence. The -following image formats are supported: - - - - - - - - - - - - - - - - - - - - - -
Supported Image Format Encoding Decoding Comments
PGM, PPM X X
PGMYUV X X PGM with U and V components in 420
JPEG X X Progressive JPEG is not supported
.Y.U.V X X One raw file per component
Animated GIF X Only uncompressed GIFs are generated
- -

-X means that the encoding (resp. decoding) is supported. - - - - -

5.3 Video Codecs

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Supported Codec Encoding Decoding Comments
MPEG1 video X X
MPEG2 video X
MPEG4 X X Also known as DIVX4/5
MSMPEG4 V1 X X
MSMPEG4 V2 X X
MSMPEG4 V3 X X Also known as DIVX3
WMV7 X X
H263(+) X X Also known as Real Video 1.0
MJPEG X X
DV X
Huff YUV X X
- -

-X means that the encoding (resp. decoding) is supported. - - -

-Check at http://www.mplayerhq.hu/~michael/codec-features.html to -get a precise comparison of FFmpeg MPEG4 codec compared to the other -solutions. - - - - -

5.4 Audio Codecs

- - - - - - - - - - - - - - - - - - - - -
Supported Codec Encoding Decoding Comments
MPEG audio layer 2 IX IX
MPEG audio layer 1/3 IX IX MP3 encoding is supported through the external library LAME -
AC3 IX X liba52 is used internally for decoding. -
Vorbis X X supported through the external library libvorbis. -
WMA V1/V2 X
- -

-X means that the encoding (resp. decoding) is supported. - - -

-I means that an integer only version is available too (ensures highest -performances on systems without hardware floating point support). - - - - -

6. Platform Specific information

- - - -

6.1 Linux

- -

-ffmpeg should be compiled with at least GCC 2.95.3. GCC 3.2 is the -preferred compiler now for ffmpeg. All future optimizations will depend on -features only found in GCC 3.2. - - - - -

6.2 BSD

- - - -

6.3 Windows

- - - -

6.4 MacOS X

- - - -

6.5 BeOS

- -

-The configure script should guess the configuration itself. -Networking support is currently not finished. -errno issues fixed by Andrew Bachmann. - - -

-Old stuff: - - -

-François Revol - revol at free dot fr - April 2002 - - -

-The configure script should guess the configuration itself, -however I still didn't tested building on net_server version of BeOS. - - -

-ffserver is broken (needs poll() implementation). - - -

-There is still issues with errno codes, which are negative in BeOs, and -that ffmpeg negates when returning. This ends up turning errors into -valid results, then crashes. -(To be fixed) - - - - -

7. Developers Guide

- - - -

7.1 API

- - - - - -

7.2 Integrating libavcodec or libavformat in your program

- -

-You can integrate all the source code of the libraries to link them -statically to avoid any version problem. All you need is to provide a -'config.mak' and a 'config.h' in the parent directory. See the defines -generated by ./configure to understand what is needed. - - -

-You can use libavcodec or libavformat in your commercial program, but -any patch you make must be published. The best way to proceed is -to send your patches to the ffmpeg mailing list. - - - - -

7.3 Coding Rules

- -

-ffmpeg is programmed in ANSI C language. GCC extensions are -tolerated. Indent size is 4. The TAB character should not be used. - - -

-The presentation is the one specified by 'indent -i4 -kr'. - - -

-Main priority in ffmpeg is simplicity and small code size (=less -bugs). - - -

-Comments: for functions visible from other modules, use the JavaDoc -format (see examples in `libav/utils.c') so that a documentation -can be generated automatically. - - - - -

7.4 Submitting patches

- -

-When you submit your patch, try to send a unified diff (diff '-u' -option). I cannot read other diffs :-) - - -

-Run the regression tests before submitting a patch so that you can -verify that there are no big problems. - - -

-Patches should be posted as base64 encoded attachments (or any other -encoding which ensures that the patch wont be trashed during -transmission) to the ffmpeg-devel mailinglist, see -http://lists.sourceforge.net/lists/listinfo/ffmpeg-devel - - - - -

7.5 Regression tests

- -

-Before submitting a patch (or committing with CVS), you should at least -test that you did not break anything. - - -

-The regression test build a synthetic video stream and a synthetic -audio stream. Then these are encoded then decoded with all codecs or -formats. The CRC (or MD5) of each generated file is recorded in a -result file. Then a 'diff' is launched with the reference results and -the result file. - - -

-The regression test then goes on to test the ffserver code with a -limited set of streams. It is important that this step runs correctly -as well. - - -

-Run 'make test' to test all the codecs. - - -

-Run 'make libavtest' to test all the codecs. - - -

-[Of course, some patches may change the regression tests results. In -this case, the regression tests reference results shall be modified -accordingly]. - - -

-This document was generated on 17 April 2003 using -texi2html 1.56k. - - diff --git a/doc/ffserver-doc.html b/doc/ffserver-doc.html deleted file mode 100644 index 2356264b11..0000000000 --- a/doc/ffserver-doc.html +++ /dev/null @@ -1,312 +0,0 @@ - - - - -FFserver Documentation - - -

FFserver Documentation

-

-

-

Table of Contents

- -

- -

-FFserver Documentation - - - - -

1. Introduction

- -

-FFserver is a streaming server for both audio and video. It supports -several live feeds, streaming from files and time shifting on live feeds -(you can seek to positions in the past on each live feed, provided you -specify a big enough feed storage in ffserver.conf). - - -

-This documentation covers only the streaming aspects of ffserver / -ffmpeg. All questions about parameters for ffmpeg, codec questions, -etc. are not covered here. Read `ffmpeg-doc.[texi|html]' for more -information. - - - - -

2. QuickStart

- -

-[Contributed by Philip Gladstone, philip-ffserver at gladstonefamily dot net] - - - - -

2.1 What can this do?

- -

-When properly configured and running, you can capture video and audio in real -time from a suitable capture card, and stream it out over the Internet to -either Windows Media Player or RealAudio player (with some restrictions). - - -

-It can also stream from files, though that is currently broken. Very often, a -web server can be used to serve up the files just as well. - - -

-It can stream prerecorded video from .ffm files, though it is somewhat tricky -to make it work correctly. - - - - -

2.2 What do I need?

- -

-I use Linux on a 900MHz Duron with a cheapo Bt848 based TV capture card. I'm -using stock linux 2.4.17 with the stock drivers. [Actually that isn't true, -I needed some special drivers from my motherboard based sound card.] - - -

-I understand that FreeBSD systems work just fine as well. - - - - -

2.3 How do I make it work?

- -

-First, build the kit. It *really* helps to have installed LAME first. Then when -you run the ffserver ./configure, make sure that you have the --enable-mp3lame -flag turned on. - - -

-LAME is important as it allows streaming of audio to Windows Media Player. Don't -ask why the other audio types do not work. - - -

-As a simple test, just run the following two command lines (assuming that you -have a V4L video capture card): - - - -

-./ffserver -f doc/ffserver.conf &
-./ffmpeg http://localhost:8090/feed1.ffm
-
- -

-At this point you should be able to go to your windows machine and fire up -Windows Media Player (WMP). Go to Open URL and enter - - - -

-    http://<linuxbox>:8090/test.asf
-
- -

-You should see (after a short delay) video and hear audio. - - -

-WARNING: trying to stream test1.mpg doesn't work with WMP as it tries to -transfer the entire file before starting to play. The same is true of avi files. - - - - -

2.4 What happens next?

- -

-You should edit the ffserver.conf file to suit your needs (in terms of -frame rates etc). Then install ffserver and ffmpeg, write a script to start -them up, and off you go. - - - - -

2.5 Troubleshooting

- - - -

2.5.1 I don't hear any audio, but video is fine

- -

-Maybe you didn't install LAME, or get your ./configure statement right. Check -the ffmpeg output to see if a line referring to mp3 is present. If not, then -your configuration was incorrect. If it is, then maybe your wiring is not -setup correctly. Maybe the sound card is not getting data from the right -input source. Maybe you have a really awful audio interface (like I do) -that only captures in stereo and also requires that one channel be flipped. -If you are one of these people, then export 'AUDIO_FLIP_LEFT=1' before -starting ffmpeg. - - - - -

2.5.2 The audio and video loose sync after a while.

- -

-Yes, they do. - - - - -

2.5.3 After a long while, the video update rate goes way down in WMP.

- -

-Yes, it does. Who knows why? - - - - -

2.5.4 WMP 6.4 behaves differently to WMP 7.

- -

-Yes, it does. Any thoughts on this would be gratefully received. These -differences extend to embedding WMP into a web page. [There are two -different object ids that you can use, one of them -- the old one -- cannot -play very well, and the new one works well (both on the same system). However, -I suspect that the new one is not available unless you have installed WMP 7]. - - - - -

2.6 What else can it do?

- -

-You can replay video from .ffm files that was recorded earlier. -However, there are a number of caveats which include the fact that the -ffserver parameters must match the original parameters used to record the -file. If not, then ffserver deletes the file before recording into it. (Now I write -this, this seems broken). - - -

-You can fiddle with many of the codec choices and encoding parameters, and -there are a bunch more parameters that you cannot control. Post a message -to the mailing list if there are some 'must have' parameters. Look in the -ffserver.conf for a list of the currently available controls. - - -

-It will automatically generate the .ASX or .RAM files that are often used -in browsers. These files are actually redirections to the underlying .ASF -or .RM file. The reason for this is that the browser often fetches the -entire file before starting up the external viewer. The redirection files -are very small and can be transferred quickly. [The stream itself is -often 'infinite' and thus the browser tries to download it and never -finishes.] - - - - -

2.7 Tips

- -

-* When you connect to a live stream, most players (WMP, RA etc) want to -buffer a certain number of seconds of material so that they can display the -signal continuously. However, ffserver (by default) starts sending data -in real time. This means that there is a pause of a few seconds while the -buffering is being done by the player. The good news is that this can be -cured by adding a '?buffer=5' to the end of the URL. This says that the -stream should start 5 seconds in the past -- and so the first 5 seconds -of the stream is sent as fast as the network will allow. It will then -slow down to real time. This noticeably improves the startup experience. - - -

-You can also add a 'Preroll 15' statement into the ffserver.conf that will -add the 15 second prebuffering on all requests that do not otherwise -specify a time. In addition, ffserver will skip frames until a key_frame -is found. This further reduces the startup delay by not transferring data -that will be discarded. - - -

-* You may want to adjust the MaxBandwidth in the ffserver.conf to limit -the amount of bandwidth consumed by live streams. - - - - -

2.8 Why does the ?buffer / Preroll stop working after a time?

- -

-It turns out that (on my machine at least) the number of frames successfully -grabbed is marginally less than the number that ought to be grabbed. This -means that the timestamp in the encoded data stream gets behind real time. -This means that if you say 'preroll 10', then when the stream gets 10 -or more seconds behind, there is no preroll left. - - -

-Fixing this requires a change in the internals in how timestamps are -handled. - - - - -

2.9 Does the ?date= stuff work.

- -

-Yes (subject to the caution above). Also note that whenever you start -ffserver, it deletes the ffm file (if any parameters have changed), thus wiping out what you had recorded -before. - - -

-The format of the ?date=xxxxxx is fairly flexible. You should use one -of the following formats (the 'T' is literal): - - - -

-* YYYY-MM-DDTHH:MM:SS     (localtime)
-* YYYY-MM-DDTHH:MM:SSZ    (UTC)
-
- -

-You can omit the YYYY-MM-DD, and then it refers to the current day. However -note that `?date=16:00:00' refers to 4PM on the current day -- this may be -in the future and so unlikely to useful. - - -

-You use this by adding the ?date= to the end of the URL for the stream. -For example: `http://localhost:8080/test.asf?date=2002-07-26T23:05:00'. - - -

-This document was generated on 28 December 2002 using -texi2html 1.56k. - - diff --git a/doc/hooks.html b/doc/hooks.html deleted file mode 100644 index d18376f283..0000000000 --- a/doc/hooks.html +++ /dev/null @@ -1,90 +0,0 @@ - - - - -Video Hook Documentation - - -

Video Hook Documentation

-

-

-

Table of Contents

- -

- -

-Video Hook Documentation - - - - -

1. Introduction

- -

-The video hook functionality is designed (mostly) for live video. It allows -the video to be modified or examined between the decoder and the encoder. - - -

-Any number of hook modules can be placed inline, and they are run in the -order that they were specified on the ffmpeg command line. - - -

-Three modules are provided and are described below. They are all intended to -be used as a base for your own modules. - - -

-Modules are loaded using the -vhook option to ffmpeg. The value of this parameter -is a space seperated list of arguments. The first is the module name, and the rest -are passed as arguments to the Configure function of the module. - - - - -

1.1 null.c

- -

-This does nothing. Actually it converts the input image to RGB24 and then converts -it back again. This is meant as a sample that you can use to test your setup. - - - - -

1.2 fish.c

- -

-This implements a 'fish detector'. Essentially it converts the image into HSV -space and tests whether more than a certain percentage of the pixels fall into -a specific HSV cuboid. If so, then the image is saved into a file for processing -by other bits of code. - - -

-Why use HSV? It turns out that HSV cuboids represent a more compact range of -colors than would an RGB cuboid. - - - - -

1.3 imlib2.c

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-This allows a caption to be placed onto each frame. It supports inserting the -time and date. By using the imlib functions, it would be easy to add your own -graphical logo, add a frame/border, etc. - - -

-This document was generated on 28 December 2002 using -texi2html 1.56k. - -