Tool mediastreamvalidator reports error "Variant media_[N].m3u8 is
missing audio group" for audio streams in HLS master playlist. As audio
streams are already listed in audio group, skip them as variant media
streams in master playlist.
SIDX atom being inserted for every MOOF atom increases the muxing overhead.
This behaviour can be disabled for chunked CMAF format by enabling Global SIDX option of mov muxer.
For example bitdepth should be printed as 10 instead of 0A. Thanks to Hendrik Leppkes for pointing this out
Signed-off-by: James Almer <jamrial@gmail.com>
Fixes bug id #7386
Muxer overhead calculations was intented for HLS playlist as Apple's mediastreamvalidator tests were failing.
But applying the same fix for DASH manifest proved counterproductive, as Bandwidth can be used for segment name templates.
Applicable only to webm output format.
By default all the segment filenames end with .m4s extension.
When someone chooses webm output format, we recommend they also override the relevant segment name options to end with .webm extension. This patch will issue a warning for he same
Right now segment file format is chosen to be either mp4 or webm based on the codec format.
This patch makes that choice configurable by the user, instead of being decided by the muxer.
Also with this change per-stream choice segment file format(based on codec type) is not possible.
All the output audio and video streams should be in the same file format.
Enables one to test possibly nonstandard formats such as Opus or
FLAC in ISOBMFF, among other things.
This becomes much more useful if output segment format becomes an
option, or if the WebM segment feature gets removed.
It has not ever been working and has not been validated,
Additionally, mention that the segment file names should be changed
to end with webm instead of m4s, which is utilized for ISOBMFF
fragments.
There is a separate muxer(webmdashenc.c) for supporting VP9+webm output in DASH.
Hence in this muxer we will focus on supporting VP9 in MP4
Have verified playout support of VP9+MP4 in Chrome and Firefox.
reference hls support fmp4 file from draft-pantos-http-live-streaming-20
the spec describes version 7 of hls protocol
Suggested-by: Ronak <ronak2121@yahoo.com>
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>
The logic is applicable only when use_template is enabled and use_timeline
is disabled. The logic monitors the flow of segment indexes. If a streams's
segment index value is not at the expected real time position, then
the logic corrects that index value.
Typically this logic is needed in live streaming use cases. The network
bandwidth fluctuations are common during long run streaming. Each
fluctuation can cause the segment indexes fall behind the expected real
time position. Without this logic, players will not be able to consume
the content, even after encoder's network condition comes back to
normal state.
availability time of Nth segment = availabilityStartTime + (N*segment duration) - availabilityTimeOffset.
This field helps to reduce the latency by about a segment duration in streaming mode.
@availabilityStartTime specifies the anchor for the computation of the earliest
availability time (in UTC) for any Segment in the Media Presentation.
As per this requirement, the @AvailabilityStartTime should be set to the
wallclock time at which the first frame of the first segment begins encoding.
But, it was getting set only when the first segment was completely ready. Making
the required correction in this patch. This correction is mainly needed to reduce
the latency in live streaming use cases.
Calling 'write_manifest' from 'write_header' was causing creation of
first MPD with invalid values. Ex: zero @duration param value. Also,
the manifest files (MPD or M3U8s) should be created when at-least
one media frame is ready for consumption.
When use_template is enabled and use_timeline is disabled, typically
it is required to generate the segments at the configured segment duration
rate on an average. This commit is particularly needed to handle the
segmentation when video frame rates are fractional like 29.97 or 59.94 fps.
There are use cases where average segment duration needs to be configured
and muxer is expected to maintain the average segment duration. So, using
the name 'min_seg_duration' will be misleading. So, changing the parameter
name to 'seg_duration', where it can be minimum segment duration or average
segment duration based on the use-case. The additional updates needed for
this functinality are made the sub-sequent patches of this patch series.
Currently http end of chunk is signalled implicitly in dashenc_io_open().
This mean playlists http writes would have to wait upto a segment duration to signal end of chunk causing delays.
This patch will fix that problem and improve performance.
This is required for AV playout from master.m3u8.
Otherwise master.m3u8 lists only video-only and/or audio-only streams.
Reviewed-by: Steven Liu <lq@chinaffmpeg.org>
This is to take full advantage of Common Media Application Format(CMAF).
Now server can generate one content and serve both HLS and DASH players.
Reviewed-by: Steven Liu <lq@onvideo.cn>
