Specifically, ff_flac_parse_streaminfo, ff_flac_is_extradata_valid and
ff_flac_parse_block_header

Specifically, ff_mpeg4audio_sample_rates, ff_mpeg4audio_get_config and
ff_copy_pce_data

Specifically, ff_mpa_freq_tab, ff_mpa_bitrate_tab, ff_mpa_decode_header,
ff_mpegaudio_decode_header.

It's used in lavf.

Overhead as reported by rbelf-size goes from 40147 to 20877.

They are used in libavdevice.

It's used in libavdevice.

enable CODEC_CAP_DELAY to flush any remaining frames in the buffer.

Stop decoding when the FN_QUIT command is found so that a trailing seek table
isn't decoded as a normal frame.

decode all channels in the same call to avcodec_decode_audio3() so that
decoding will not stop after the first channel of the last frame.

Updated FATE reference. More valid audio is now decoded.

decode_subframe_lpc().

just set data_size to zero.

fixes incorrect bitrate reporting and potential misreporting of the number of
channels.

Having it there forces decoding of a frame in order to get frame_size, but it
is not really needed for proper demuxing or decoding.

The first timestamp should be negative due to delay.
Also, do not set AVCodecContext.frame_size unnecessarily.

Using AVCodecContext.frame_size is not reliable.

This avoids some unused variable warnings with YASM disabled.

This is done conditional to the libavcodec version to avoid ABI breaks.

This fixes 'make checkheaders' on non-W32THREADS systems.

Deprecate avcodec_get_context_defaults/avcodec_get_context_defaults2

Manual replacements are done in this commit.

In many cases, the id is some constant made up number (e.g. 0 for video
and 1 for audio), which is then not used in the demuxer for anything.
Those ids are removed.