Abort with error if calculated bitrate is too low.

Added bc_run_test function to tidy up real-number comparisons.
Rewrote messages for B-frames. Apparently the DivX-HT spec allows
only single non-consecutive B-frames; confirmed on test H/W players.

Added bc_run_test function; used to tidy up real number comparisons.
Removed stray double-quote character from help message.
Minor comment clarification on OpenDML headers.
Further clarification on comments and error messages.
Significant rewrite.

Now uses bc-coprocess.
Dynamically reformatted help message.
-H and -W scaling constraints.
Converting 50/60fps progressive scan to interlaced.
Can use xvid to encode.
Ensure lavc/xvid don't exceed maximum DivX HT bitrates.
By default scales to use MPEG-4 PAR, can also scale to enforce square pixels.
More accurate storage->bitrate calculator.
Allows any bitrate MPEG-1 layer II audio.
Can also encode audio to Dolby AC-3 or MPEG-4 AAC.
Dry-run mode.
Long GNU-style options, fall back on single-letter options if
    GNU getopt(1) not installed.
720->704px wide hack for ITU-R BT.601.
Optional enabling of OpenDML for players that can handle >2GiB.
Warns if output file size would exceed 2GiB.
Minor cosmetic source reformatting.

Replaced missing USE_XVID=0.
Minor cosmetic source / error message formatting.
Added -E option as alternative to -7 hack.

Checks if output directory is writable.

Further clarifications in help message.
Adding .gitignore
Removed comment describing need for `mkfifo' command; this command is
also present on at least FreeBSD and Mac OS X, and is likely
POSIX-mandated too.
Replace `echo' with `printf' where arguments may begin with a dash.

Simply bc_run_cmds.

Fixed $ID_WIDTH -> $ID_VIDEO_WIDTH
Now unsets OUTPUT_FILENAME.
Accounted for pan & scan and 720px -> aspect*=45/44 hack combination; this
should produce an image 540px wide rather than 704px -> 528px.
Added -a -l -p -Q command line options for disabling certain checks when they
are not relevant, or testing for square pixels.

Now also tests for standard MPEG-4 PARs.
Added file size limit option (-S).
Special handling for frame rates of 50fps, 59.94fps or 60fps.
Major rewrite. Borrows a lot of stuff from rewritten encode-divxht script.

Added zoom-to-aspect feature (-Z).

Added xvid encoding option (-X).

Bitrate calculator is far more accurate now.

No longer allows MPEG-1 layer II audio in output (the Cowon D2 refuses to play
back this format in DivX files), now transcodes to layer III instead.

Checks if 2GiB file size would be exceeded.

Pan & scan cropping is done before scaling. The old script did these in the wrong
order, which caused MPlayer to waste CPU cycles scaling pixels on the sides of
16:9 pictures that would inevitably be cropped.

Aspects narrower than 4:3 will result in only the image width being padded out
to a multiple of 16px.

Can now de-interlace interlaced footage as well (-I).

Special cases for frame rates 50fps, 59.94fps and 60fps; the frame rate will be
halved in this case (allows watching speedrun videos).
Added URL for official DivX profile technical specs document.