Download ===== https://cinurl.com/2tkBG2
Each input or output url can, in principle, contain any number of streams ofdifferent types (video/audio/subtitle/attachment/data). The allowed number and/ortypes of streams may be limited by the container format. Selecting whichstreams from which inputs will go into which output is either done automaticallyor with the -map option (see the Stream selection chapter).
ffmpeg provides the -map option for manual control of stream selection in eachoutput file. Users can skip -map and let ffmpeg perform automatic stream selection asdescribed below. The -vn / -an / -sn / -dn options can be used to skip inclusion ofvideo, audio, subtitle and data streams respectively, whether manually mapped or automaticallyselected, except for those streams which are outputs of complex filtergraphs.
In the absence of any map options for a particular output file, ffmpeg inspects the outputformat to check which type of streams can be included in it, viz. video, audio and/orsubtitles. For each acceptable stream type, ffmpeg will pick one stream, when available,from among all the inputs.
Stream handling is independent of stream selection, with an exception for subtitles describedbelow. Stream handling is set via the -codec option addressed to streams within aspecific output file. In particular, codec options are applied by ffmpeg after thestream selection process and thus do not influence the latter. If no -codec option isspecified for a stream type, ffmpeg will select the default encoder registered by the outputfile muxer.
An exception exists for subtitles. If a subtitle encoder is specified for an output file, thefirst subtitle stream found of any type, text or image, will be included. ffmpeg does not validateif the specified encoder can convert the selected stream or if the converted stream is acceptablewithin the output format. This applies generally as well: when the user sets an encoder manually,the stream selection process cannot check if the encoded stream can be muxed into the output file.If it cannot, ffmpeg will abort and all output files will fail to be processed.
The 2nd output file, out2.srt, only accepts text-based subtitle streams. So, even thoughthe first subtitle stream available belongs to C.mkv, it is image-based and hence skipped.The selected stream, stream 2 in B.mp4, is the first text-based subtitle stream.
Add an attachment to the output file. This is supported by a few formatslike Matroska for e.g. fonts used in rendering subtitles. Attachmentsare implemented as a specific type of stream, so this option will adda new stream to the file. It is then possible to use per-stream optionson this stream in the usual way. Attachment streams created with thisoption will be created after all the other streams (i.e. those createdwith -map or automatic mappings).
This lowers the latency of subtitles for which the end packet or the followingsubtitle has not yet been received. As a drawback, this will most likely leadto duplication of subtitle events in order to cover the full duration, sowhen dealing with use cases where latency of when the subtitle event is passedon to output is not relevant this option should not be utilized.
Requires -fix_sub_duration to be set for the relevant input subtitlestream for this to have any effect, as well as for the input subtitle streamhaving to be directly mapped to the same output in which the heartbeat streamresides.
Fix subtitles durations. For each subtitle, wait for the next packet in thesame stream and adjust the duration of the first to avoid overlap. This isnecessary with some subtitles codecs, especially DVB subtitles, because theduration in the original packet is only a rough estimate and the end isactually marked by an empty subtitle frame. Failing to use this option whennecessary can result in exaggerated durations or muxing failures due tonon-monotonic timestamps.
As a special exception, you can use a bitmap subtitle stream as input: itwill be converted into a video with the same size as the largest video inthe file, or 720x576 if no video is present. Note that this is anexperimental and temporary solution. It will be removed once libavfilter hasproper support for subtitles.
Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletextsubtitles. Requires the presence of the libzvbi headers and library duringconfiguration. You need to explicitly configure the build with--enable-libzvbi.
List of teletext page numbers to decode. Pages that do not match the specifiedlist are dropped. You may use the special * string to match all pages,or subtitle to match all subtitle pages.Default value is *.
Chops leading and trailing spaces and removes empty lines from the generatedtext. This option is useful for teletext based subtitles where empty spaces maybe present at the start or at the end of the lines or empty lines may bepresent between the subtitle lines because of double-sized teletext characters.Default value is 1.
Sets the opacity (0-255) of the teletext background. Iftxt_transparent is not set, it only affects characters between a startbox and an end box, typically subtitles. Default value is 0 iftxt_transparent is set, 255 otherwise.
When set to 1, enable a work-around that makes the number of pixel rowseven in all subtitles. This fixes a problem with some players thatcut off the bottom row if the number is odd. The work-around just addsa fully transparent row if needed. The overhead is low, typicallyone byte per subtitle on average.
When shifting is enabled, all output timestamps are shifted by thesame amount. Audio, video, and subtitles desynching and relativetimestamp differences are preserved compared to how they would havebeen without shifting.
Start the playlist sequence number (#EXT-X-MEDIA-SEQUENCE) according to the specified source.Unless hls_flags single_file is set, it also specifies source of starting sequence numbers ofsegment and subtitle filenames. In any case, if hls_flags append_listis set and read playlist sequence number is greater than the specified start sequence number,then that value will be used as start value.
Start the playlist sequence number (#EXT-X-MEDIA-SEQUENCE) from the specified numberwhen hls_start_number_source value is generic. (This is the default case.)Unless hls_flags single_file is set, it also specifies starting sequence numbers of segment and subtitle filenames.Default value is 0.
Map string which specifies how to group the audio, video and subtitle streamsinto different variant streams. The variant stream groups are separatedby space.Expected string format is like this \"a:0,v:0 a:1,v:1 ....\". Here a:, v:, s: arethe keys to specify audio, video and subtitle streams respectively.Allowed values are 0 to 9 (limited just based on practical usage).
Every track with disposition default will have the FlagDefault set.Additionally, for each type of track (audio, video or subtitle), if no trackwith disposition default of this type exists, then the first track of this typewill be marked as default (if existing). This ensures that the default flagis set in a sensible way even if the input originated from containers thatlack the concept of default tracks. 59ce067264