Added default values, correct strings for default model path and pool
method.

Option wait_for_tc only takes effect if tc_format is set

The number of bits in a PutBitContext must fit into an int, yet nothing
guaranteed the size argument cbs_write_unit_data() uses in init_put_bits()
to be in the range 0..INT_MAX / 8. This has been changed.

Furthermore, the check 8 * data_size > data_bit_start that there is
data beyond the initial padding when writing mpeg2 or H.264/5 slices
could also overflow, so divide it by 8 to get an equivalent check
without this problem.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

All cbs-functions to write units share a common pattern:
1. They check whether they have a write buffer (that is used to store
the unit's data until the needed size becomes known after writing the
unit when a dedicated buffer will be allocated).
2. They use this buffer for a PutBitContext.
3. The (codec-specific) writing takes place through the PutBitContext.
4. The return value is checked. AVERROR(ENOSPC) here always indicates
that the buffer was too small and leads to a reallocation of said
buffer.
5. The final buffer will be allocated and the data copied.

This commit factors this common code out in a single function in cbs.c.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>

flac_read_timestamp() applied av_init_packet() to a packet (which
initializes all fields of the packet except for data and size) and then
went on to use only the data and size fields. In other words: Said
packet can be removed and replaced by an uint8_t * and an int.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

Mentioned in ticket #8378.

Mentioned in ticket #8378.

Mentioned in ticket #8378.

Signed-off-by: Rick Kern <kernrj@gmail.com>