On 21/07/2020 21:05, Pierre-Louis Bossart wrote:
On 7/21/20 12:00 PM, Srinivas Kandagatla wrote:
For gapless playback it is possible that each track can have different
codec profile with same decoder, for example we have WMA album,
we may have different tracks as WMA v9, WMA v10 and so on
Or if DSP's like QDSP have abililty to switch decoders on single stream
ability
for each track, then this call could be used to set new codec parameters.
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.
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
.../sound/designs/compress-offload.rst | 6 ++++
include/sound/compress_driver.h | 5 +++
include/uapi/sound/compress_offload.h | 1 +
sound/core/compress_offload.c | 34 +++++++++++++++++++
4 files changed, 46 insertions(+)
diff --git a/Documentation/sound/designs/compress-offload.rst
b/Documentation/sound/designs/compress-offload.rst
index 935f325dbc77..305ccc7bfdd9 100644
--- a/Documentation/sound/designs/compress-offload.rst
+++ b/Documentation/sound/designs/compress-offload.rst
@@ -128,6 +128,12 @@ set_params
cases decoders will ignore other fields, while encoders will strictly
comply to the settings
+set_codec_params
+ This routine is very much simillar to set_params but exculding stream
typos: similar, excluding
+ information. Only codec related information is set as part of this.
+ It is used in gapless playback where its required to change decoder
+ or its parameters for next track. This is optional.
+
get_params
This routines returns the actual settings used by the DSP. Changes to
the settings should remain the exception.
diff --git a/include/sound/compress_driver.h
b/include/sound/compress_driver.h
index 70cbc5095e72..d9c00bcfce9b 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,
Optional
+ * This can be called in during gapless next track codec change only
to set
+ * codec params
Would it be clearer if this was called set_next_codec_params()? or
set_next_track_codec_params()?
Having set_params() and set_codec_params() is a bit confusing since the
semantic difference is not captured in the callback name.
set_next_track_codec_params seems more sensible as its next track params.
Will change this in next version!
--srini
