On Wed, 11 Aug 2010, Takashi Iwai wrote:
> At Wed, 11 Aug 2010 10:59:59 +0200,
> I wrote:
> >
> > At Wed, 11 Aug 2010 09:04:32 +0100 (BST),
> > Mark Hills wrote:
> > >
> > > Hi, does anybody have any thoughts on my email below? The rate conversion
> > > code looks stable and untouched for a while.
> >
> > I guess it's a missing support of 3-byte formats in 16bit conversion,
> > so not specific to rate plugin.
Indeed, it's an obvious ommision now that you mention it! Thanks for the
hint.
> > Adding the support shouldn't be too hard, since it's already found
> > in 32bit conversion.
>
> A quick (untested) fix is below.
Thanks, I tested your patch.
There's a minor mistake that prevents it working, and a couple of comments
don't seem quite right (see below). I'll follow this email with a revised
patch.
With my modified patch, I was able to play back reliably in both aplay and
xwax on my S24_3BE device with rate conversion.
> diff --git a/src/pcm/pcm_linear.c b/src/pcm/pcm_linear.c
> index 12e2e7f..01b6742 100644
> --- a/src/pcm/pcm_linear.c
> +++ b/src/pcm/pcm_linear.c
> @@ -114,10 +114,9 @@ int snd_pcm_linear_get32_index(snd_pcm_format_t src_format, snd_pcm_format_t dst
>
> int snd_pcm_linear_put_index(snd_pcm_format_t src_format, snd_pcm_format_t dst_format)
> {
> - int sign, width, endian;
> + int sign, width, pwidth, endian;
> sign = (snd_pcm_format_signed(src_format) !=
> snd_pcm_format_signed(dst_format));
> - width = snd_pcm_format_width(dst_format) / 8 - 1;
> #ifdef SND_LITTLE_ENDIAN
> endian = snd_pcm_format_big_endian(dst_format);
> #else
> @@ -125,7 +124,23 @@ int snd_pcm_linear_put_index(snd_pcm_format_t src_format, snd_pcm_format_t dst_f
> #endif
> if (endian < 0)
> endian = 0;
> - return width * 4 + endian * 2 + sign;
> + pwidth = snd_pcm_format_physical_width(dst_format);
> + width = snd_pcm_format_width(dst_format) / 8 - 1;
I concluded this conversion is mis-placed, as it is done again, below (and
affects decision making when pwidth == 24)
> + if (pwidth == 24) {
> + switch (width) {
> + case 24:
> + width = 0; break;
> + case 20:
> + width = 1; break;
> + case 18:
> + default:
> + width = 2; break;
> + }
> + return width * 4 + endian * 2 + sign + 16;
> + } else {
> + width = width / 8 - 1;
I left this conversion in.
> + return width * 4 + endian * 2 + sign;
> + }
> }
>
> int snd_pcm_linear_put32_index(snd_pcm_format_t src_format, snd_pcm_format_t dst_format)
> diff --git a/src/pcm/plugin_ops.h b/src/pcm/plugin_ops.h
> index 04220d6..0c63ca6 100644
> --- a/src/pcm/plugin_ops.h
> +++ b/src/pcm/plugin_ops.h
> @@ -407,7 +407,7 @@ get16_123_B2_18: sample = (_get_triple_s(src) >> 2) ^ 0x8000; goto GET16_END;
>
> #ifdef PUT16_LABELS
> /* dst_wid dst_endswap sign_toggle */
> -static void *const put16_labels[4 * 2 * 2] = {
> +static void *const put16_labels[4 * 2 * 2 + 4 * 3] = {
> &&put16_12_1, /* 16h -> 8h */
> &&put16_12_9, /* 16h ^> 8h */
> &&put16_12_1, /* 16h -> 8s */
> @@ -424,6 +424,19 @@ static void *const put16_labels[4 * 2 * 2] = {
> &&put16_12_9200, /* 16h ^> 32h */
> &&put16_12_0021, /* 16h -> 32s */
> &&put16_12_0029, /* 16h ^> 32s */
> + /* 3bytes format */
> + &&put16_12_120, /* 16h -> 24h */
> + &&put16_12_920, /* 16h ^> 24h */
> + &&put16_12_021, /* 16h -> 24s */
> + &&put16_12_029, /* 16h ^> 24h */
> + &&put16_12_120_20, /* 16h -> 20h */
> + &&put16_12_920_20, /* 16h ^> 20h */
> + &&put16_12_021_20, /* 16h -> 20s */
> + &&put16_12_029_20, /* 16h ^> 20h */
> + &&put16_12_120_18, /* 16h -> 18h */
> + &&put16_12_920_18, /* 16h ^> 18h */
> + &&put16_12_021_18, /* 16h -> 18s */
> + &&put16_12_029_18, /* 16h ^> 18h */
A couple of the comments here look wrong, as they are repeats. '20h' and
'18h' become '20s' and '18s' respectively. I have corrected that in the
follow up patch.
> };
> #endif
>
[...]
--
Mark
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