From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
To: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>, broonie@kernel.org
Cc: alsa-devel@alsa-project.org, ckeepax@opensource.cirrus.com,
linux-kernel@vger.kernel.org, tiwai@suse.com,
lgirdwood@gmail.com, vkoul@kernel.org
Subject: Re: [PATCH 10/11] ASoC: qdsp6-dai: add gapless support
Date: Wed, 8 Jul 2020 11:58:21 -0500 [thread overview]
Message-ID: <b0aa1cff-33c9-a44d-b17b-d2e4e42d60f1@linux.intel.com> (raw)
In-Reply-To: <e6d10009-d01e-d506-1aa3-a915ef42a693@linaro.org>
>> right, but the key point is 'switch between streams'. That means a
>> more complex/capable implementation that should be advertised as such
>> to applications. This is not the default behavior assumed initially:
>> to allow for minimal implementations in memory-constrained devices, we
>> assumed gapless was supported with a single decoder.
>>
>> Maybe the right way to do this is extend the snd_compr_caps structure:
>>
>> /**
>> * struct snd_compr_caps - caps descriptor
>> * @codecs: pointer to array of codecs
>> * @direction: direction supported. Of type snd_compr_direction
>> * @min_fragment_size: minimum fragment supported by DSP
>> * @max_fragment_size: maximum fragment supported by DSP
>> * @min_fragments: min fragments supported by DSP
>> * @max_fragments: max fragments supported by DSP
>> * @num_codecs: number of codecs supported
>> * @reserved: reserved field
>> */
>> struct snd_compr_caps {
>> __u32 num_codecs;
>> __u32 direction;
>> __u32 min_fragment_size;
>> __u32 max_fragment_size;
>> __u32 min_fragments;
>> __u32 max_fragments;
>> __u32 codecs[MAX_NUM_CODECS];
>> __u32 reserved[11];
>> } __attribute__((packed, aligned(4)));
>>
>>
>> and use a reserved field to provide info on capabilities, and filter
>> the set_codec_params() addition based this capability - i.e. return
>> -ENOTSUP in 'traditional' implementations based on a single
>> 'stream'/decoder instance.
I think this is also what Mark was referring to earlier.
> Sounds good!
> I will give it a go and see how it ends up!
Glad to see this discussion progressing.
We may also want to document the 3 possible ways of supporting gapless
playback while we are at it:
a) with the existing single decoder assumption
b) with your suggested solution with a switch at the DSP level
c) with 2 streams at the userspace level and a switch/x-fade at the DSP
level - which may simplify userspace quite a bit and was the initial
design in a non-Linux OS.
next prev parent reply other threads:[~2020-07-08 16:59 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-07 16:36 [PATCH 00/11] ASoC: qdsp6: add gapless compressed audio support Srinivas Kandagatla
2020-07-07 16:36 ` [PATCH 01/11] ASoC: q6asm: add command opcode to timeout error report Srinivas Kandagatla
2020-07-07 16:36 ` [PATCH 02/11] ASoC: q6asm: rename misleading session id variable Srinivas Kandagatla
2020-07-07 16:36 ` [PATCH 03/11] ASoC: q6asm: make commands specific to streams Srinivas Kandagatla
2020-07-07 16:52 ` Pierre-Louis Bossart
2020-07-08 9:44 ` Srinivas Kandagatla
2020-07-08 13:13 ` Mark Brown
2020-07-08 15:26 ` Srinivas Kandagatla
2020-07-07 16:36 ` [PATCH 04/11] ASoC: q6asm: use flags directly from asm-dai Srinivas Kandagatla
2020-07-07 16:36 ` [PATCH 05/11] ASoC: q6asm: add length to write command token Srinivas Kandagatla
2020-07-07 16:36 ` [PATCH 06/11] ASoC: q6asm: add support to remove intial and trailing silence Srinivas Kandagatla
2020-07-07 16:55 ` Pierre-Louis Bossart
2020-07-08 9:44 ` Srinivas Kandagatla
2020-07-07 16:36 ` [PATCH 07/11] ASoC: q6asm: add support to gapless flag in asm open Srinivas Kandagatla
2020-07-07 16:57 ` Pierre-Louis Bossart
2020-07-08 9:44 ` Srinivas Kandagatla
2020-07-07 16:36 ` [PATCH 08/11] ASoC: q6asm-dai: add next track metadata support Srinivas Kandagatla
2020-07-07 16:36 ` [PATCH 09/11] ASoC: qdsp6: use dev_err instead of pr_err Srinivas Kandagatla
2020-07-07 16:36 ` [PATCH 10/11] ASoC: qdsp6-dai: add gapless support Srinivas Kandagatla
2020-07-07 17:07 ` Pierre-Louis Bossart
2020-07-08 9:44 ` Srinivas Kandagatla
2020-07-08 13:32 ` Pierre-Louis Bossart
2020-07-08 13:42 ` Mark Brown
2020-07-08 15:23 ` Srinivas Kandagatla
2020-07-08 16:58 ` Pierre-Louis Bossart [this message]
2020-07-07 16:36 ` [PATCH 11/11] ASoC: q6asm-dai: add support to copy callback Srinivas Kandagatla
2020-07-08 13:32 ` [PATCH 00/11] ASoC: qdsp6: add gapless compressed audio support Mark Brown
2020-07-08 15:24 ` Srinivas Kandagatla
2020-07-08 16:59 ` Mark Brown
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