From: Rene Herman <rene.herman@keyaccess.nl>
To: Andreas Mueller <andreas@stapelspeicher.org>
Cc: tiwai@suse.de, ALSA devel <alsa-devel@alsa-project.org>,
linux-kernel@vger.kernel.org, MatzeBraun@gmx.de
Subject: Re: [PATCH] es1968: fix jitter on some maestro cards
Date: Tue, 01 Apr 2008 00:24:43 +0200 [thread overview]
Message-ID: <47F164AB.5040009@keyaccess.nl> (raw)
In-Reply-To: <20080329234943.GA2899@slappy>
[-- Attachment #1: Type: text/plain, Size: 741 bytes --]
On 30-03-08 00:49, Andreas Mueller wrote:
> This patch suppresses jitter on several Maestro cards in stereo mode
> (ALSA of course).
>
> The patch is also incorporated in the *BSD drivers where I "ported" it from.
> I am barely used to driver-development so please take a look (esp. the channel
> parameters), nevertheless it completely works for me.
>
> Without this patch most of the stereo audio gets out of sync and really
> distorted (oss-emulation with mplayer at 48000khz worked somehow).
>
> CCed to those listed in the .c file.
Added the alsa-devel list (and re-attached the patch). My TerraTec DMX (ESS
Canyon3D, ES1970MS-3D) doesn't need this but doesn't seem to suffer from it
either. Otherwise no idea about this.
Rene.
[-- Attachment #2: es1968_jitter.patch --]
[-- Type: text/plain, Size: 990 bytes --]
--- sound/pci/es1968.c.old 2008-03-29 19:17:16.771116317 +0100
+++ sound/pci/es1968.c 2008-03-30 00:14:35.363057160 +0100
@@ -1816,7 +1816,24 @@
return 0;
}
+/*
+ * suppress jitter on some maestros when playing stereo
+ */
+static void snd_es1968_suppress_jitter(struct es1968 *chip, struct esschan *es)
+{
+ unsigned int cp1;
+ unsigned int cp2;
+ unsigned int diff;
+ cp1 = __apu_get_register(chip, 0, 5);
+ cp2 = __apu_get_register(chip, 1, 5);
+ diff = (cp1 > cp2 ? cp1 - cp2 : cp2 - cp1);
+
+ if (diff > 1) {
+ __maestro_write(chip, IDR0_DATA_PORT, cp1);
+ }
+}
+
/*
* update pointer
*/
@@ -1937,8 +1954,11 @@
struct esschan *es;
spin_lock(&chip->substream_lock);
list_for_each_entry(es, &chip->substream_list, list) {
- if (es->running)
+ if (es->running) {
snd_es1968_update_pcm(chip, es);
+ if (es->fmt & ESS_FMT_STEREO)
+ snd_es1968_suppress_jitter(chip, es);
+ }
}
spin_unlock(&chip->substream_lock);
if (chip->in_measurement) {
[-- Attachment #3: Type: text/plain, Size: 160 bytes --]
_______________________________________________
Alsa-devel mailing list
Alsa-devel@alsa-project.org
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
WARNING: multiple messages have this Message-ID (diff)
From: Rene Herman <rene.herman@keyaccess.nl>
To: Andreas Mueller <andreas@stapelspeicher.org>
Cc: linux-kernel@vger.kernel.org, MatzeBraun@gmx.de, tiwai@suse.de,
ALSA devel <alsa-devel@alsa-project.org>
Subject: Re: [PATCH] es1968: fix jitter on some maestro cards
Date: Tue, 01 Apr 2008 00:24:43 +0200 [thread overview]
Message-ID: <47F164AB.5040009@keyaccess.nl> (raw)
In-Reply-To: <20080329234943.GA2899@slappy>
[-- Attachment #1: Type: text/plain, Size: 741 bytes --]
On 30-03-08 00:49, Andreas Mueller wrote:
> This patch suppresses jitter on several Maestro cards in stereo mode
> (ALSA of course).
>
> The patch is also incorporated in the *BSD drivers where I "ported" it from.
> I am barely used to driver-development so please take a look (esp. the channel
> parameters), nevertheless it completely works for me.
>
> Without this patch most of the stereo audio gets out of sync and really
> distorted (oss-emulation with mplayer at 48000khz worked somehow).
>
> CCed to those listed in the .c file.
Added the alsa-devel list (and re-attached the patch). My TerraTec DMX (ESS
Canyon3D, ES1970MS-3D) doesn't need this but doesn't seem to suffer from it
either. Otherwise no idea about this.
Rene.
[-- Attachment #2: es1968_jitter.patch --]
[-- Type: text/plain, Size: 990 bytes --]
--- sound/pci/es1968.c.old 2008-03-29 19:17:16.771116317 +0100
+++ sound/pci/es1968.c 2008-03-30 00:14:35.363057160 +0100
@@ -1816,7 +1816,24 @@
return 0;
}
+/*
+ * suppress jitter on some maestros when playing stereo
+ */
+static void snd_es1968_suppress_jitter(struct es1968 *chip, struct esschan *es)
+{
+ unsigned int cp1;
+ unsigned int cp2;
+ unsigned int diff;
+ cp1 = __apu_get_register(chip, 0, 5);
+ cp2 = __apu_get_register(chip, 1, 5);
+ diff = (cp1 > cp2 ? cp1 - cp2 : cp2 - cp1);
+
+ if (diff > 1) {
+ __maestro_write(chip, IDR0_DATA_PORT, cp1);
+ }
+}
+
/*
* update pointer
*/
@@ -1937,8 +1954,11 @@
struct esschan *es;
spin_lock(&chip->substream_lock);
list_for_each_entry(es, &chip->substream_list, list) {
- if (es->running)
+ if (es->running) {
snd_es1968_update_pcm(chip, es);
+ if (es->fmt & ESS_FMT_STEREO)
+ snd_es1968_suppress_jitter(chip, es);
+ }
}
spin_unlock(&chip->substream_lock);
if (chip->in_measurement) {
next prev parent reply other threads:[~2008-03-31 22:22 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-29 23:49 [PATCH] es1968: fix jitter on some maestro cards Andreas Mueller
2008-03-31 22:24 ` Rene Herman [this message]
2008-03-31 22:24 ` Rene Herman
2008-04-14 10:22 ` Takashi Iwai
2008-04-14 10:22 ` Takashi Iwai
2008-04-14 10:43 ` Rene Herman
2008-04-14 10:43 ` Rene Herman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=47F164AB.5040009@keyaccess.nl \
--to=rene.herman@keyaccess.nl \
--cc=MatzeBraun@gmx.de \
--cc=alsa-devel@alsa-project.org \
--cc=andreas@stapelspeicher.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tiwai@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.