1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00
Go to file
Andreas Rheinhardt d0bd00c8eb avformat/oggenc: Avoid allocating and copying when writing page data
When the Ogg muxer writes a page, it has to do three things: It needs to
write a page header, then it has to actually copy the page data and then
it has to calculate and write a CRC checksum of both header as well as
data at a certain position in the page header.

To do this, the muxer used a dynamic buffer for both writing as well as
calculating the checksum via an AVIOContext's feature to automatically
calculate checksums on the data it writes. This entails an allocation of
an AVIOContext, of the opaque specific to dynamic buffers and of the
buffer itself (which may be reallocated multiple times) as well as
memcopying the data (first into the AVIOContext's small write buffer,
then into the dynamic buffer's big buffer).

This commit changes this: The page header is no longer written into a
dynamic buffer any more; instead the (small) page header is written into
a small buffer on the stack. The CRC is then calculated directly via
av_crc() on both the page header as well as the page data. Then both the
page header and the page data are written.

Finally, ogg_write_page() can now no longer fail, so it has been
modified to return nothing; this also fixed a bug in the only caller of
this function: It didn't check the return value.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
2020-05-09 16:18:39 +02:00
compat compat/avisynth: remove avisynth headers 2020-04-05 01:17:55 +02:00
doc doc/encoders: remove unsubstantiated ffaacenc > fdk-aac claim 2020-05-08 11:10:01 -08:00
ffbuild common.mak: Also clean Windows debug files. 2020-03-21 18:46:00 +01:00
fftools fftools/ffmpeg: use local variable with same contents directly 2020-05-06 23:02:00 +08:00
libavcodec avcodec/mpegvideo: return more specific error codes for init_duplicate_context() 2020-05-09 09:33:49 +08:00
libavdevice avfoundation: Fix building on iOS 2020-04-30 14:21:47 +02:00
libavfilter dnn/native: add native support for minimum 2020-05-08 15:22:27 +08:00
libavformat avformat/oggenc: Avoid allocating and copying when writing page data 2020-05-09 16:18:39 +02:00
libavresample
libavutil avutil/opt: only skip evaluation for rational options 2020-05-01 17:22:58 +02:00
libpostproc libavcodec, libpostproc: Remove outcommented START/STOP_TIMER 2020-03-14 18:24:04 +01:00
libswresample Silence "string-plus-int" warning shown by clang. 2020-01-06 22:38:56 +01:00
libswscale libswscale: add output support for AV_PIX_FMT_GBRAPF32 2020-05-05 20:06:58 +02:00
presets
tests dnn-layer-mathbinary-test: add unit test for minimum 2020-05-08 15:22:44 +08:00
tools dnn/native: add native support for minimum 2020-05-08 15:22:27 +08:00
.gitattributes
.gitignore tools/python: add script to convert TensorFlow model (.pb) to native model (.model) 2019-07-01 10:23:47 -03:00
.mailmap mailmap: fix 3-address entries 2020-03-31 04:14:14 -05:00
.travis.yml
Changelog avcodec/pcm_rechunk_bsf: add bitstream filter to rechunk pcm audio 2020-05-07 23:12:24 +02:00
configure avformat/audiointerleave: only keep the retime functionality of the audio interleaver 2020-05-07 23:12:24 +02:00
CONTRIBUTING.md
COPYING.GPLv2
COPYING.GPLv3
COPYING.LGPLv2.1
COPYING.LGPLv3
CREDITS
INSTALL.md
LICENSE.md avfilter/vf_geq: Relicense to LGPL 2019-12-28 11:20:48 +01:00
MAINTAINERS MAINTAINERS: Add myself to libopenh264enc 2020-05-06 19:12:00 +02:00
Makefile Makefile: Delete more created files when running "make distclean". 2020-03-11 11:43:01 +01:00
README.md
RELEASE RELEASE: Update value for post 4.2 branch 2019-07-21 18:37:32 +02:00

FFmpeg README

FFmpeg is a collection of libraries and tools to process multimedia content such as audio, video, subtitles and related metadata.

Libraries

  • libavcodec provides implementation of a wider range of codecs.
  • libavformat implements streaming protocols, container formats and basic I/O access.
  • libavutil includes hashers, decompressors and miscellaneous utility functions.
  • libavfilter provides a mean to alter decoded Audio and Video through chain of filters.
  • libavdevice provides an abstraction to access capture and playback devices.
  • libswresample implements audio mixing and resampling routines.
  • libswscale implements color conversion and scaling routines.

Tools

  • ffmpeg is a command line toolbox to manipulate, convert and stream multimedia content.
  • ffplay is a minimalistic multimedia player.
  • ffprobe is a simple analysis tool to inspect multimedia content.
  • Additional small tools such as aviocat, ismindex and qt-faststart.

Documentation

The offline documentation is available in the doc/ directory.

The online documentation is available in the main website and in the wiki.

Examples

Coding examples are available in the doc/examples directory.

License

FFmpeg codebase is mainly LGPL-licensed with optional components licensed under GPL. Please refer to the LICENSE file for detailed information.

Contributing

Patches should be submitted to the ffmpeg-devel mailing list using git format-patch or git send-email. Github pull requests should be avoided because they are not part of our review process and will be ignored.