On Sun, May 22, 2011 at 06:32:36PM -0400, Justin Ruggles wrote:
>
> --- a/doc/encoders.texi
> +++ b/doc/encoders.texi
> @@ -365,4 +365,47 @@ is highly recommended that it be left as enabled except
> for testing purposes.
>
> +@table @option
> +
> +@item -channel_coupling @var{boolean}
> +Channel Coupling. Enables/Disables use of channel coupling, which is an
The first two words seem redundant. Thankfully this option name is not
so cryptic that it needs to be decoded.
> +optional AC-3 feature that increases quality by combining high frequency
> +information from multiple channels into a single channel. The per-channel
> high
> +frequency information is sent with less accuracy in both the frequency and
> time
> +domains. This allows more bits to be used for lower frequencies while
> preserving
> +enough information to reconstruct the high frequencies. This option is
> enabled
> +by default for the floating-point encoder and should generally be left as
> +enabled except for testing purposes or to increase encoding speed.
I'd say s/left as enabled/left enabled/. However, you are a native
speaker, so don't hesitate to discard any or all of my comments if
you feel your wording is better.
> +@table @option
> +@item -1
> +@itemx auto
> +Selected by Encoder (default)
.
> +@item 0
> +@itemx off
> +Disable Channel Coupling
.
> +@item 1
> +@itemx on
> +Enable Channel Coupling
.
> +@item -cpl_start @var{number}
> +Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
Maybe the option could receive a slightly longer and less cryptic name?
This is probably something we could and should discuss in general. Many
of our option names are quite cryptic. I'd prefer self-explanatory names
at the expense of typing a few more characters.
> +value higher than the bandwidth is used, it will be reduced to 1 less than
> the
> +coupling end band. If @var{auto} is used, the start band will be determined
> by
> +the encoder based on the bit rate, sample rate, and channel layout.
> +@table @option
> +@item -1
> +@itemx auto
> +Selected by Encoder (default)
.
> --- a/libavcodec/ac3enc.c
> +++ b/libavcodec/ac3enc.c
> @@ -2084,11 +2590,54 @@ static av_cold void set_bandwidth(AC3EncodeContext *s)
> +
> + s->start_freq[CPL_CH] = (cpl_start_band * 12) + 37;
> + s->cpl_end_freq = (cpl_end_band * 12) + 37;
pointless ()
> --- a/libavcodec/ac3tab.c
> +++ b/libavcodec/ac3tab.c
> @@ -138,6 +138,12 @@ const uint16_t ff_ac3_bitrate_tab[19] = {
>
> +/**
> + * Table E2.16 Default Coupling Banding Structure
> + */
> +const uint8_t ff_eac3_default_cpl_band_struct[18] =
> +{ 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1 };
Indentation missing.
Diego
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