I am working on ffmpeg and x265 for video encoding. From the release note of x265:
HDR10+ supported. Dynamic metadata may be either supplied as a bitstream via the userSEI field of x265_picture, or as a json jile that can be parsed by x265 and inserted into the bitstream; use --dhdr10-info to specify json file name, and --dhdr10-opt to enable optimization of inserting tone-map information only at IDR frames, or when the tone map information changes.
But I dont know how to export the dynamic metadata from a video sequence as a userSEI or json file. Hope to get solution from you.
Related
I have a PDF which was encoded using Object Streams. I would like to parse this PDF for further processing with other generated PDFs. Most PDF gems I have used claim Object Streams are not supported.
How have you dealt with parsing object streams?
I am currently using CombinePDF. When I try to load the PDF, CombinePDF chokes on parsing this PDF.
Ideally, I would like to take a PDF which has object streams, remove the object streams, save the PDF as a new PDF file without object streams.
Other gems I've tried, Origami, Yomu, and PDF Reader, all do a lazy parsing.
I know this is possible because I achieved this using Preview on OS X. I opened the said file with Preview on OS X and "Export to PDF…", the new file did not have object streams. How can I reproduce this action in code?
To create a video from a powerpoint presentation I can use for example
ppFile.CreateVideo fileName, false, 1, 793, 2, 100
How can I define the format of the output file.
Obviously I can call the fileName foo.mp4 or foo.wav but I have my doubts that this really changes the way the video is encoded as apposed to just changing the suffix of the file.
What is the default encoding method and how can one select a different encoding method?
Thanks
The output is WMV, if you want a different format you must convert using a transcoding utility, for example the ffmpeg command line tool.
I want to embed metadata about a particular stream with in a mpeg2ts. which is the best field with in transport stream to embed this information. Can i embed this information with in the adaptation field of the mpeg2ts header.
Thank you
Guru
Under MPEG 2 systems standard there potentially two ways to do this.
One can either define a user private table. See Table 2-26 : table_id 0x40-0xFE See. section 2.4.4.10 Syntax of the Private section.
Or one can define user private stream. See Table 2-29 stream id under PES packet as 0x80 to 0xFF).
Refer to ISO/IEC 13818-1 MPEG 2 Systems.
I am looking for specifications for the ogg vorbis header packet format. I have searched the Internet without much success. Where can I find one?
http://en.wikipedia.org/wiki/Ogg#Page_structure describes what every single page in an ogg file looks like -- file metadata and stream data alike.
http://xiph.org/vorbis/doc/Vorbis_I_spec.html actually describes the contents of a ogg vorbis file's metadata (header) pages. The three header packets are:
an Identification Header,
a Comment Header, and
a Setup Header.
The specification requires that all three of these headers be present.
A bitfield diagram of the Ogg Vorbis identification header is at http://wiki.xiph.org/OggVorbis.
Hope this is what you're looking for:
http://xiph.org/vorbis/doc/v-comment.html
Where can I find documentation/sample code of the VOBsub subtitles format? The one that's an .idx and a .sub file.
I need to create a program that generates those subtitles. I've been looking on Google but only found how to rip them from DVD.
Thanks
VOBsub extracts the DVD subtitles raw PES from a DVD and dumps this to a .sub file. It also creates a .idx Index file with the times and byteoffsets for each and every single subtitle. The format has support for multiple tracks and can also be embedded in MP4 (by Nero) and Matroska files.
Technical specs vobsub
Technical specs from Matroska.org
Example files: Specs_and_idx-sub_files.rar
Have a look at these open source implementations:
BDSup2Sub (Java)
Subtitle Edit (C#)
guliverkli by gabest (C++) check out VSFilter and VSRip; original implementation
Son2VobSub.rar (C++)
And then there are the media players like VLC. You can also check out these threads on doom9:
http://forum.doom9.org/archive/index.php/t-87171.html
http://forum.doom9.org/archive/index.php/t-99815.html
I think your best approach would be to have a look at the sourcecode of some of the open-source media players. Some of them will have the code to interpret an .idx or .sub subtitle file.
This might be a useful starting point:
http://sourceforge.net/projects/guliverkli/