[RFC PATCH] ALSA: compress: add support to change codec profile in gapless playback
Srinivas Kandagatla
srinivas.kandagatla at linaro.org
Thu Jul 2 14:29:43 CEST 2020
Thanks Vinod for quick review,
On 02/07/2020 12:36, Vinod Koul wrote:
> Hi Srini,
>
> On 02-07-20, 12:11, Srinivas Kandagatla wrote:
>> For gapless playback its possible that each track can have different
>
> s/its/it is
>
>> codec profile with same decoder, for example we have WMA album,
>> we may have different tracks as WMA v9, WMA v10 and so on
>>
>> Existing code does not allow to change this profile while doing gapless
>> playback.
>>
>> This patch adds new SNDRV_COMPRESS_SET_CODEC_PARAMS IOCTL to allow
>> userspace to set this new parameters required for new codec profile.
>
> Thanks, this looks good and in line with discussions done in Audio uConf
>
>>
>> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla at linaro.org>
>> ---
>> include/sound/compress_driver.h | 5 +++
>> include/sound/soc-component.h | 3 ++
>> include/sound/soc-dai.h | 5 +++
>> include/uapi/sound/compress_offload.h | 1 +
>> sound/core/compress_offload.c | 54 ++++++++++++++++++++++++---
>> sound/soc/soc-compress.c | 30 +++++++++++++++
>> sound/soc/soc-dai.c | 14 +++++++
>
> Can we split the ALSA changes and ASoC changes to different patches
> please?
>
> Also please post driver support for this API..
Yes, q6dsp gapless patches are the users for this api, I will include
them in next version.
>
> Lastly, documentation needs update about this call
>
I will fix these in next version!
>> 7 files changed, 106 insertions(+), 6 deletions(-)
>>
>> diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
>> index 70cbc5095e72..8d23351f7ad7 100644
>> --- a/include/sound/compress_driver.h
>> +++ b/include/sound/compress_driver.h
>> @@ -93,6 +93,9 @@ struct snd_compr_stream {
>> * @set_params: Sets the compressed stream parameters, mandatory
>> * This can be called in during stream creation only to set codec params
>> * and the stream properties
>> + * @set_codec_params: Sets the compressed stream codec parameters, mandatory
>
> This should be optional as gapless is optional
>
>> --- a/include/uapi/sound/compress_offload.h
>> +++ b/include/uapi/sound/compress_offload.h
>> @@ -172,6 +172,7 @@ struct snd_compr_metadata {
>> struct snd_compr_metadata)
>> #define SNDRV_COMPRESS_GET_METADATA _IOWR('C', 0x15,\
>> struct snd_compr_metadata)
>> +#define SNDRV_COMPRESS_SET_CODEC_PARAMS _IOW('C', 0x16, struct snd_codec)
>> #define SNDRV_COMPRESS_TSTAMP _IOR('C', 0x20, struct snd_compr_tstamp)
>> #define SNDRV_COMPRESS_AVAIL _IOR('C', 0x21, struct snd_compr_avail)
>> #define SNDRV_COMPRESS_PAUSE _IO('C', 0x30)
>
> I think we should bump the compress version too for checking in userland
> about this support
Sure!
>
>> static int snd_compress_check_input(struct snd_compr_params *params)
>> {
>> /* first let's check the buffer parameter's */
>> @@ -574,14 +586,41 @@ static int snd_compress_check_input(struct snd_compr_params *params)
>> params->buffer.fragments == 0)
>> return -EINVAL;
>>
>> - /* now codec parameters */
>> - if (params->codec.id == 0 || params->codec.id > SND_AUDIOCODEC_MAX)
>> - return -EINVAL;
>> + return snd_compress_check_codec_params(¶ms->codec);
>
> Can this be 1st patch to prepare for this change?
>
>>
>> - if (params->codec.ch_in == 0 || params->codec.ch_out == 0)
>> - return -EINVAL;
>> +}
>>
>> - return 0;
>> +static int snd_compr_set_codec_params(struct snd_compr_stream *stream,
>> + unsigned long arg)
>> +{
>> + struct snd_codec *params;
>> + int retval;
>> +
>> + if (!stream->ops->set_codec_params)
>> + return -EPERM;
>> +
>> + if (stream->runtime->state != SNDRV_PCM_STATE_RUNNING)
>> + return -EPERM;
>> +
>> + /* codec params can be only set when next track has been signalled */
>> + if (stream->next_track == false)
>> + return -EPERM;
>> +
>> + params = memdup_user((void __user *)arg, sizeof(*params));
>> + if (IS_ERR(params))
>> + return PTR_ERR(params);
>> +
>> + retval = snd_compress_check_codec_params(params);
>> + if (retval)
>> + goto out;
>> +
>> + retval = stream->ops->set_codec_params(stream, params);
>> + if (retval)
>> + goto out;
>
> this jump is superfluous
yes, we could just remove the check!
>
>> +
>> +out:
>> + kfree(params);
>> + return retval;
>> }
>
> ...
>
>> +static int soc_compr_set_codec_params(struct snd_compr_stream *cstream,
>> + struct snd_codec *codec)
>> +{
>> + struct snd_soc_pcm_runtime *rtd = cstream->private_data;
>> + struct snd_soc_component *component;
>> + struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
>> + int i, ret;
>> +
>> + mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
>> +
>> + ret = snd_soc_dai_compr_set_codec_params(cpu_dai, cstream, codec);
>> + if (ret < 0)
>> + goto err;
>> +
>> + for_each_rtd_components(rtd, i, component) {
>> + if (!component->driver->compress_ops ||
>> + !component->driver->compress_ops->set_codec_params)
>> + continue;
>> +
>> + ret = component->driver->compress_ops->set_codec_params(component, cstream,
>> + codec);
>
> maybe use a compress_ops pointer to make this look and read better :)
Sure will do that!
--srini
>
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