avfilter_graph_request_oldest() does work that should be done by
either the filter or the application.

The principle of this function, calling ff_request_frame() from
outside the filter was always shaky. This version is less elegant
since it requires making special cases for each filter, but it
is more robust since it no longer calls ff_request_frame()
directly without notifying the filter.

Eventually, avfilter_graph_request_oldest() will be deprecated
for a function to just run the graph.

ff_request_frame_to_filter() and ff_filter_frame_to_filter()
are only used in avfilter.c.

Having two different functions allows to have stricter tests
and detect errors earlier.

It does not change anything for the existing filters and makes
better code fatrorization when future code will use the utility
functions.

Unlike av_frame_is_writable(), it uses the link's alloc callback,
making direct rendering possible.

The code comes from ff_filter_frame_framed(), moved with mostly
trivial changes.

Also introduce libavfilter/filters.h for all functions needed
to implement filters.

av_buffersink_get_frame_rate() did already exist; its argument becomes const.

The names are only used for technical output and debugging.
Make them similar to C identifiers for easier quick reading
of debug dumps.

start_number option starts the playlist sequence number
(#EXT-X-MEDIA-SEQUENCE) from the specified number. Unless hls_flags
single_file is set, it also specifies starting sequence numbers of
segment and subtitle filenames. Sometimes it is usefull to have unique
starting numbers at each run, but currently it is only achiveable by
setting this parameter manually.
This patch enables to specify start_number source parameter by
introducing hls_start_number_source with 3 possible values:
generic/epoch/datetime. This ensures to set start sequence number
automatically for practically unique numbers. Generic option is the
default and this is the curent behaviour: start_number option value
specifies the start sequence number. (start_number default value is 0)
If hls_start_number_source is set to epoch, then the start number will
be the seconds since epoch (1970-01-01 00:00:00). If set to datetime,
then the start sequence number will be based on the current date/time
value as YYYYmmddHHMMSS. e.g. 20161231235659.
Hls speficication allows 64 bit integers as sequence numbers. This patch
also changes some code where only 32 bit integer values were handled
correctly.
Reviewed-by: Moritz Barsnick <barsnick@gmx.net>
Signed-off-by: Bela Bodecs <bodecsb@vivanet.hu>
Signed-off-by: Steven Liu <lq@chinaffmpeg.org>

Signed-off-by: James Almer <jamrial@gmail.com>

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Reason: For some cases, such as 2 or more graphics cards existing, the
default command line may fail because ffmpeg does not open the correct
device node:
    ffmpeg -hwaccel qsv -c:v h264_qsv -i test.264 -c:v h264_qsv out.264
Let user choose the proper one by running like below:
    ffmpeg -hwaccel qsv -qsv_device /dev/dri/renderD128 -c:v h264_qsv \
-i test.264 -c:v h264_qsv out.264
Signed-off-by: ChaoX A Liu <chaox.a.liu@gmail.com>
Signed-off-by: Huang, Zhengxu <zhengxu.maxwell@gmail.com>
Signed-off-by: Andrew, Zhang <huazh407@gmail.com>
Signed-off-by: Mark Thompson <sw@jkqxz.net>

Fixes ticket #6072.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

This decoder can decode all existing SpeedHQ formats (SHQ0–5, 7, and 9),
including correct decoding of the alpha channel.

1080p is decoded in 142 fps on one core of my i7-4600U (2.1 GHz Haswell),
about evenly split between bitstream reader and IDCT. There is currently
no attempt at slice or frame threading, even though the format trivially
supports both.

NewTek very helpfully provided a full set of SHQ samples, as well as
source code for an SHQ2 encoder (not included) and assistance with
understanding some details of the format.

Allows more codecs than mpeg12video to make use of it.

Mainly useful for supporting decoding of headerless files.
Signed-off-by: Paul B Mahol <onemda@gmail.com>