From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Anssi Hannula <anssi.hannula@iki.fi>
Cc: Fabio Estevam <fabio.estevam@freescale.com>,
alsa-devel@alsa-project.org, dri-devel@lists.freedesktop.org,
Mark Brown <broonie@kernel.org>, Yakir Yang <ykk@rock-chips.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [alsa-devel] [PATCH 12/13] drm: bridge/dw_hdmi-ahb-audio: add audio driver
Date: Sat, 9 May 2015 18:53:28 +0100 [thread overview]
Message-ID: <20150509175327.GU2067@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20150509174054.GT2067@n2100.arm.linux.org.uk>
On Sat, May 09, 2015 at 06:40:54PM +0100, Russell King - ARM Linux wrote:
> Even VLC _doesn't_ if it's outputting to a standard audio - in other
> words, if you don't tick the SPDIF direct output option which defaults
> to disabled (which, when enabled, opens the device passing the AES
> bits _and_ permits it to send a compressed audio stream.) I've looked
> at this in VLC many times...
FYI, here's the code:
vlc_fourcc_t fourcc = aout->format.i_format;
bool spdif = false;
switch (fourcc)
{
... other linear float/integer codec IDs ...
case VLC_CODEC_U16B:
pcm_format = SND_PCM_FORMAT_U16_BE;
break;
case VLC_CODEC_U16L:
pcm_format = SND_PCM_FORMAT_U16_LE;
break;
...
default:
if (AOUT_FMT_SPDIF(&aout->format))
spdif = var_InheritBool (aout, "spdif");
if (spdif)
{
fourcc = VLC_CODEC_SPDIFL;
pcm_format = SND_PCM_FORMAT_S16;
}
else
if (HAVE_FPU)
{
fourcc = VLC_CODEC_FL32;
pcm_format = SND_PCM_FORMAT_FLOAT;
}
else
{
fourcc = VLC_CODEC_S16N;
pcm_format = SND_PCM_FORMAT_S16;
}
}
/* Choose the IEC device for S/PDIF output:
if the device is overridden by the user then it will be the one.
Otherwise we compute the default device based on the output format. */
if (spdif && !strcmp (device, "default"))
{
unsigned aes3;
switch (aout->format.i_rate)
{
#define FS(freq) \
case freq: aes3 = IEC958_AES3_CON_FS_ ## freq; break;
FS( 44100) /* def. */ FS( 48000) FS( 32000)
FS( 22050) FS( 24000)
FS( 88200) FS(768000) FS( 96000)
FS(176400) FS(192000)
#undef FS
default:
aes3 = IEC958_AES3_CON_FS_NOTID;
break;
}
free (device);
if (asprintf (&device,
"iec958:AES0=0x%x,AES1=0x%x,AES2=0x%x,AES3=0x%x",
IEC958_AES0_CON_EMPHASIS_NONE | IEC958_AES0_NONAUDIO,
IEC958_AES1_CON_ORIGINAL | IEC958_AES1_CON_PCM_CODER,
0, aes3) == -1)
return VLC_ENOMEM;
}
...
/* VLC always has a resampler. No need for ALSA's. */
const int mode = SND_PCM_NO_AUTO_RESAMPLE;
int val = snd_pcm_open (&pcm, device, SND_PCM_STREAM_PLAYBACK, mode);
So, the result is:
* VLC opens the ALSA device _without_ AES information if the fourcc
being passed if the format is a linear PCM type.
* If the format is not a linear PCM type _and_ it is a format which
satisfies AOUT_FMT_SPDIF(), _and_ the SPDIF passthrough option is
enabled, _then_ we open the IEC958 audio output device with the
first four AES data bytes specified with SND_PCM_FORMAT_S16.
Moreover, the first data byte always indicates that the stream is
non-audio.
So, in the case of linear PCM, the AES data bytes are *not* specified
by VLC.
So, if we don't have the kernel driver specifying the IEC958 information
for HDMI/SPDIF outputs, and users of ALSA's userspace APIs don't generate
them for linear PCM, how are the required AES data bytes generated?
--
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/dri-devel
next prev parent reply other threads:[~2015-05-09 17:53 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-02 9:20 [RFC v2 0/13] dw_hdmi cleanups, audio preparation, helpers and ahb audio support Russell King - ARM Linux
2015-04-02 9:21 ` [PATCH RFC v2 01/13] drm: imx/dw_hdmi: move phy comments Russell King
2015-04-02 9:21 ` [PATCH RFC v2 02/13] drm: bridge/dw_hdmi: clean up phy configuration Russell King
2015-04-02 9:21 ` [PATCH RFC v2 03/13] drm: bridge/dw_hdmi: clean up hdmi_set_clk_regenerator() Russell King
2015-04-02 9:21 ` [PATCH RFC v2 04/13] drm: bridge/dw_hdmi: use drm_hdmi_avi_infoframe_from_display_mode() Russell King
2015-04-02 9:21 ` [PATCH RFC v2 05/13] drm: bridge/dw_hdmi: simplify hdmi_config_AVI() a little Russell King
2015-04-02 9:21 ` [PATCH RFC v2 06/13] drm: bridge/dw_hdmi: remove mhsyncpolarity/mvsyncpolarity/minterlaced Russell King
2015-04-02 9:21 ` [PATCH RFC v2 07/13] drm: bridge/dw_hdmi: introduce interface to setting sample rate Russell King
2015-04-02 9:21 ` [PATCH RFC v2 08/13] drm: bridge/dw_hdmi: introduce interfaces to enable and disable audio Russell King
2015-04-02 9:22 ` [PATCH RFC v2 09/13] drm/edid: add function to help find SADs Russell King
2015-04-02 9:22 ` [PATCH RFC v2 10/13] sound/core: add DRM ELD helper Russell King
2015-04-05 15:57 ` Takashi Iwai
2015-04-05 16:20 ` Russell King - ARM Linux
2015-04-05 16:46 ` Takashi Iwai
2015-04-05 17:26 ` Russell King - ARM Linux
2015-05-06 17:02 ` Anssi Hannula
2015-05-07 10:41 ` Russell King - ARM Linux
2015-05-07 11:11 ` Lars-Peter Clausen
2015-05-08 10:56 ` [alsa-devel] " Jyri Sarha
2015-05-08 11:42 ` Russell King - ARM Linux
2015-05-05 22:35 ` Mark Brown
2015-05-06 8:58 ` Liam Girdwood
2015-05-08 13:16 ` [alsa-devel] " Jyri Sarha
2015-05-08 13:27 ` Russell King - ARM Linux
2015-05-08 13:37 ` Jyri Sarha
2015-04-02 9:22 ` [PATCH RFC v2 11/13] sound/core: add IEC958 channel status helper Russell King
2015-04-02 9:22 ` [PATCH RFC v2 12/13] drm: bridge/dw_hdmi-ahb-audio: add audio driver Russell King
2015-04-02 9:22 ` [PATCH RFC v2 13/13] drm: bridge/dw_hdmi-ahb-audio: parse ELD from HDMI driver Russell King
2015-05-09 10:25 ` [PATCH v3 0/13] dw_hdmi cleanups, audio preparation, helpers and ahb audio support Russell King - ARM Linux
2015-05-09 10:25 ` [PATCH 01/13] drm: imx/dw_hdmi: move phy comments Russell King
2015-05-09 10:26 ` [PATCH 02/13] drm: bridge/dw_hdmi: clean up phy configuration Russell King
2015-05-22 15:19 ` Yakir
2015-05-09 10:26 ` [PATCH 03/13] drm: bridge/dw_hdmi: clean up hdmi_set_clk_regenerator() Russell King
2015-05-22 15:22 ` Yakir
2015-05-09 10:26 ` [PATCH 04/13] drm: bridge/dw_hdmi: use drm_hdmi_avi_infoframe_from_display_mode() Russell King
2015-05-09 10:26 ` [PATCH 05/13] drm: bridge/dw_hdmi: simplify hdmi_config_AVI() a little Russell King
2015-05-09 10:26 ` [PATCH 06/13] drm: bridge/dw_hdmi: remove mhsyncpolarity/mvsyncpolarity/minterlaced Russell King
2015-05-09 10:26 ` [PATCH 07/13] drm: bridge/dw_hdmi: introduce interface to setting sample rate Russell King
2015-05-22 15:26 ` Yakir
2015-05-09 10:26 ` [PATCH 08/13] drm: bridge/dw_hdmi: introduce interfaces to enable and disable audio Russell King
2015-05-22 15:28 ` Yakir
2015-05-09 10:26 ` [PATCH 09/13] drm/edid: add function to help find SADs Russell King
2015-05-09 10:26 ` [PATCH 10/13] sound/core: add DRM ELD helper Russell King
2015-05-22 12:20 ` [alsa-devel] " Mark Brown
2015-05-22 13:15 ` Russell King - ARM Linux
2015-05-22 13:30 ` Takashi Iwai
2015-05-22 13:53 ` Russell King - ARM Linux
2015-05-22 13:54 ` Takashi Iwai
2015-05-22 14:00 ` Russell King - ARM Linux
2015-05-22 14:02 ` Takashi Iwai
2015-05-22 14:05 ` Takashi Iwai
2015-05-22 16:12 ` Russell King - ARM Linux
2015-05-09 10:26 ` [PATCH 11/13] sound/core: add IEC958 channel status helper Russell King
2015-05-22 12:40 ` Mark Brown
2015-05-09 10:26 ` [PATCH 12/13] drm: bridge/dw_hdmi-ahb-audio: add audio driver Russell King
2015-05-09 16:49 ` [alsa-devel] " Anssi Hannula
2015-05-09 16:55 ` Russell King - ARM Linux
2015-05-09 17:07 ` Anssi Hannula
2015-05-09 17:40 ` Russell King - ARM Linux
2015-05-09 17:53 ` Russell King - ARM Linux [this message]
2015-05-09 17:55 ` Anssi Hannula
2015-05-09 18:11 ` Russell King - ARM Linux
2015-05-10 18:59 ` Anssi Hannula
2015-05-10 19:33 ` Russell King - ARM Linux
2015-05-10 20:47 ` Anssi Hannula
2015-05-11 15:58 ` Mark Brown
2015-05-09 10:26 ` [PATCH 13/13] drm: bridge/dw_hdmi-ahb-audio: parse ELD from HDMI driver Russell King
2015-05-27 10:43 ` Daniel Vetter
2015-05-27 11:43 ` Mark Brown
2015-05-27 17:31 ` Russell King - ARM Linux
2015-05-27 21:29 ` Daniel Vetter
2015-05-27 21:44 ` Russell King - ARM Linux
2015-05-28 6:43 ` Daniel Vetter
2015-05-28 4:56 ` [alsa-devel] " Takashi Iwai
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=20150509175327.GU2067@n2100.arm.linux.org.uk \
--to=linux@arm.linux.org.uk \
--cc=alsa-devel@alsa-project.org \
--cc=anssi.hannula@iki.fi \
--cc=broonie@kernel.org \
--cc=dri-devel@lists.freedesktop.org \
--cc=fabio.estevam@freescale.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=ykk@rock-chips.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).