opus - Sep 2016 - [PATCH] Fix ambisonics bitrate when bitrate_bps is OPUS_AUTO

Change-Id: I16bd4cd990d8ad5888c9e30016218ac25242ecb5
---
 src/opus_multistream_encoder.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/opus_multistream_encoder.c b/src/opus_multistream_encoder.c
index 30cafe1..c07132f 100644
--- a/src/opus_multistream_encoder.c
+++ b/src/opus_multistream_encoder.c
@@ -747,7 +747,8 @@ static void ambisonics_rate_allocation(
 
    if (st->bitrate_bps==OPUS_AUTO)
    {
-      total_rate = num_channels * (20000 +
st->layout.nb_streams*(Fs+60*Fs/frame_size));
+      total_rate = (st->layout.nb_coupled_streams +
st->layout.nb_streams) *
+         (Fs+60*Fs/frame_size) + st->layout.nb_streams * 15000;
    } else if (st->bitrate_bps==OPUS_BITRATE_MAX)
    {
       total_rate = num_channels * 320000;
-- 
2.8.0.rc3.226.g39d4020

15000 was chosen so that 4 channels at 48k and 60ms frames would be
256kbps. Everything else was chosen to match surround allocation as much as
possible.

On Wed, Sep 7, 2016 at 5:26 PM, Michael Graczyk <mgraczyk at google.com>
wrote:
> Change-Id: I16bd4cd990d8ad5888c9e30016218ac25242ecb5
> ---
>  src/opus_multistream_encoder.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/src/opus_multistream_encoder.c b/src/opus_multistream_
> encoder.c
> index 30cafe1..c07132f 100644
> --- a/src/opus_multistream_encoder.c
> +++ b/src/opus_multistream_encoder.c
> @@ -747,7 +747,8 @@ static void ambisonics_rate_allocation(
>
>     if (st->bitrate_bps==OPUS_AUTO)
>     {
> -      total_rate = num_channels * (20000 +
st->layout.nb_streams*(Fs+60*
> Fs/frame_size));
> +      total_rate = (st->layout.nb_coupled_streams +
> st->layout.nb_streams) *
> +         (Fs+60*Fs/frame_size) + st->layout.nb_streams * 15000;
>     } else if (st->bitrate_bps==OPUS_BITRATE_MAX)
>     {
>        total_rate = num_channels * 320000;
> --
> 2.8.0.rc3.226.g39d4020
>
>

-- 

Thanks,
Michael Graczyk
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Hi Michael,

Thanks for the fix. It's now merged in master.

	Jean-Marc

On 07/09/16 06:26 PM, Michael Graczyk wrote:
> Change-Id: I16bd4cd990d8ad5888c9e30016218ac25242ecb5
> ---
>  src/opus_multistream_encoder.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/src/opus_multistream_encoder.c
b/src/opus_multistream_encoder.c
> index 30cafe1..c07132f 100644
> --- a/src/opus_multistream_encoder.c
> +++ b/src/opus_multistream_encoder.c
> @@ -747,7 +747,8 @@ static void ambisonics_rate_allocation(
>  
>     if (st->bitrate_bps==OPUS_AUTO)
>     {
> -      total_rate = num_channels * (20000 +
st->layout.nb_streams*(Fs+60*Fs/frame_size));
> +      total_rate = (st->layout.nb_coupled_streams +
st->layout.nb_streams) *
> +         (Fs+60*Fs/frame_size) + st->layout.nb_streams * 15000;
>     } else if (st->bitrate_bps==OPUS_BITRATE_MAX)
>     {
>        total_rate = num_channels * 320000;
>