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Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound p
From: |
Programmingkid |
Subject: |
Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect |
Date: |
Fri, 16 Oct 2015 09:54:12 -0400 |
On Oct 16, 2015, at 8:15 AM, Stefan Hajnoczi wrote:
> On Tue, Sep 22, 2015 at 07:32:01PM -0400, Programmingkid wrote:
>> The USB audio card would not play audio well because its buffer was too
>> small.
>> Increasing it made it play perfectly. All the crackling and dropouts are
>> gone.
>>
>> Signed-off-by: John Arbuckle <address@hidden>
>>
>> ---
>> This patch was tested on qemu-system-ppc running Linux and qemu-system-i386
>> running Windows XP. Windows XP sound output thru the USB audio card sounded
>> perfect. Linux did improve in sound quality, but it still wasn't perfect. I
>> think there are problems with the hcd-ohci.c file. The Mac OS 10.2 guest in
>> qemu-system-ppc did not play sound due to USB issues unrelated to this
>> patch.
>>
>> hw/usb/dev-audio.c | 3 ++-
>> 1 files changed, 2 insertions(+), 1 deletions(-)
>>
>> diff --git a/hw/usb/dev-audio.c b/hw/usb/dev-audio.c
>> index f092bb8..e4e4989 100644
>> --- a/hw/usb/dev-audio.c
>> +++ b/hw/usb/dev-audio.c
>> @@ -88,6 +88,7 @@ static const USBDescStrings usb_audio_stringtable = {
>> #define USBAUDIO_PACKET_SIZE 192
>> #define USBAUDIO_SAMPLE_RATE 48000
>> #define USBAUDIO_PACKET_INTERVAL 1
>> +#define BUFFER_MULTIPLIER 32
>>
>> static const USBDescIface desc_iface[] = {
>> {
>> @@ -664,7 +665,7 @@ static const VMStateDescription vmstate_usb_audio = {
>> static Property usb_audio_properties[] = {
>> DEFINE_PROP_UINT32("debug", USBAudioState, debug, 0),
>> DEFINE_PROP_UINT32("buffer", USBAudioState, buffer,
>> - 8 * USBAUDIO_PACKET_SIZE),
>> + BUFFER_MULTIPLIER * USBAUDIO_PACKET_SIZE),
>
> I'm not familiar with the code but I guess this also increases audio
> latency by a factor of 4 (8 -> 32).
Didn't hear any problems. When I tried it out.
> Gerd might have an opinion on whether that is okay or not.
I doubt it. I don't even think he is with QEMU anymore. He doesn't
even answer simple emails. He probably stopped working on
QEMU. I do think it is time to add another USB maintainer.
- Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect, Stefan Hajnoczi, 2015/10/16
- Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect,
Programmingkid <=
- Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect, Peter Maydell, 2015/10/16
- Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect, Stefan Hajnoczi, 2015/10/26
- Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect, Gerd Hoffmann, 2015/10/26
- Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect, Programmingkid, 2015/10/26
- Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect, Stefan Hajnoczi, 2015/10/28
- Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect, Gerd Hoffmann, 2015/10/28
- Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect, Programmingkid, 2015/10/28
- Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect, Stefan Hajnoczi, 2015/10/29
- Re: [Qemu-devel] [PATCH] hw/usb/dev-audio.c: make USB audio card sound perfect, Programmingkid, 2015/10/29