Add support for AVC separate fields #94
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
philipnbbc
force-pushed
the
philipn-avc-separate-fields
branch
from
ff768c3 to
dd24bd6
Compare
Added ParseFrameSize2() and ParseFrameInfo2() essence parser methods that are given / return a ParsedFrameSize object that holds frame parse state and supports separate fields. These methods are called rather than the old (version 1) methods and if a parser does not implement them (which is all but the AVC parser) then the new method calls the old method. The previous AVCEssenceParser was renamed to AVCCodedPictureEssenceParser and it is limited to parsing a coded picture (frame coded or field coded). The AVCEssenceParser was changed to support frames or separate field pairs. The AVCWriteHelper was updated to handle the fields (access units / codec pictures) when calculating the index and AVC sub-descriptor properties.
Handle case where a B-frame is before a IDR frame in presentation order but after it in coded order. The B-frame can only have backward prediction and the key frame offset is to the IDR frame.
rather than at the end of the provided data which would result in both fields of separate fields being parsed.
The frame size may be determined outside the parser (e.g. if the remaining bytes are assumed to be part of the frame) and this method allows the state to be reset.
Signal access to parameter sets in every access unit over the other availability flags. Signal access to a parameter set in every GOP over only present in the first access unit if there is only 1 GOP.
philipnbbc
force-pushed
the
philipn-avc-separate-fields
branch
from
dd24bd6 to
3ce05f2
Compare
|
People don't say it enough, but 'thank you' Phil for everything you're doing and you've been doing over the years for the open source community. This was the last piece of the puzzle to have a proper AVC Long GOP support. It's been a while since September 2022, but the puzzle is now complete and I'm sure a lot of people are gonna be happy about this. :) |
|
Thanks! It's important for us to promote standards and ensure everyone can benefit and participate. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This PR adds support for separate field coded AVC that are stored as a pair of fields in MXF.
The
AVCEssenceParseris renamed toAVCCodedPictureEssenceParser, supporting parsing pictures. A new frame / separate field parser (AVCEssenceParser) has been added. The newAVCEssenceParserwill identify frame or fields and combine field pairs. TheEssenceParserand child classes now haveParseFrameSize2andParseFrameInfo2methods that return / use aParsedFrameSizeobject that handles the info related to a frame or pair of fields.The
AVCWriteHelperhas been updated to process fields fromAVCEssenceParserto calculate the AVC Sub-descriptor properties.The
bmxparserhas a--avc-pictureoption to dump picture (frame or single field) info rather than frame or field pair info.The file and essence provided by #86 is now supported.