ALSA: compress: add support for gapless playback

this add new API for sound compress to support gapless playback.
As noted in Documentation change, we add API to send metadata of encoder and
padding delay to DSP. Also add API for indicating EOF and switching to
subsequent track

Also bump the compress API version

Signed-off-by: Jeeja KP <jeeja.kp@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

2 files changed, 38 insertions, 1 deletions

diff --git a/include/sound/compress_driver.h b/include/sound/compress_driver.h
index f2912abacdf3..ff6c74153fa1 100644
--- a/include/sound/compress_driver.h
+++ b/include/sound/compress_driver.h
@@ -71,6 +71,8 @@ struct snd_compr_runtime {
  * @runtime: pointer to runtime structure
  * @device: device pointer
  * @direction: stream direction, playback/recording
+ * @metadata_set: metadata set flag, true when set
+ * @next_track: has userspace signall next track transistion, true when set
  * @private_data: pointer to DSP private data
  */
 struct snd_compr_stream {
@@ -79,6 +81,8 @@ struct snd_compr_stream {
         struct snd_compr_runtime *runtime;
         struct snd_compr *device;
         enum snd_compr_direction direction;
+        bool metadata_set;
+        bool next_track;
         void *private_data;
 };
 
@@ -110,6 +114,10 @@ struct snd_compr_ops {
                         struct snd_compr_params *params);
         int (*get_params)(struct snd_compr_stream *stream,
                         struct snd_codec *params);
+        int (*set_metadata)(struct snd_compr_stream *stream,
+                        struct snd_compr_metadata *metadata);
+        int (*get_metadata)(struct snd_compr_stream *stream,
+                        struct snd_compr_metadata *metadata);
         int (*trigger)(struct snd_compr_stream *stream, int cmd);
         int (*pointer)(struct snd_compr_stream *stream,
                         struct snd_compr_tstamp *tstamp);
diff --git a/include/uapi/sound/compress_offload.h b/include/uapi/sound/compress_offload.h
index 05341a43fedf..d630163b9a2e 100644
--- a/include/uapi/sound/compress_offload.h
+++ b/include/uapi/sound/compress_offload.h
@@ -30,7 +30,7 @@
 #include <sound/compress_params.h>
 
 
-#define SNDRV_COMPRESS_VERSION SNDRV_PROTOCOL_VERSION(0, 1, 0)
+#define SNDRV_COMPRESS_VERSION SNDRV_PROTOCOL_VERSION(0, 1, 1)
 /**
  * struct snd_compressed_buffer: compressed buffer
  * @fragment_size: size of buffer fragment in bytes
@@ -122,6 +122,27 @@ struct snd_compr_codec_caps {
 };
 
 /**
+ * @SNDRV_COMPRESS_ENCODER_PADDING: no of samples appended by the encoder at the
+ * end of the track
+ * @SNDRV_COMPRESS_ENCODER_DELAY: no of samples inserted by the encoder at the
+ * beginning of the track
+ */
+enum {
+        SNDRV_COMPRESS_ENCODER_PADDING = 1,
+        SNDRV_COMPRESS_ENCODER_DELAY = 2,
+};
+
+/**
+ * struct snd_compr_metadata: compressed stream metadata
+ * @key: key id
+ * @value: key value
+ */
+struct snd_compr_metadata {
+         __u32 key;
+         __u32 value[8];
+};
+
+/**
  * compress path ioctl definitions
  * SNDRV_COMPRESS_GET_CAPS: Query capability of DSP
  * SNDRV_COMPRESS_GET_CODEC_CAPS: Query capability of a codec
@@ -145,6 +166,10 @@ struct snd_compr_codec_caps {
                                                 struct snd_compr_codec_caps)
 #define SNDRV_COMPRESS_SET_PARAMS       _IOW('C', 0x12, struct snd_compr_params)
 #define SNDRV_COMPRESS_GET_PARAMS       _IOR('C', 0x13, struct snd_codec)
+#define SNDRV_COMPRESS_SET_METADATA     _IOW('C', 0x14,\
+                                                 struct snd_compr_metadata)
+#define SNDRV_COMPRESS_GET_METADATA     _IOWR('C', 0x15,\
+                                                 struct snd_compr_metadata)
 #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)
@@ -152,10 +177,14 @@ struct snd_compr_codec_caps {
 #define SNDRV_COMPRESS_START            _IO('C', 0x32)
 #define SNDRV_COMPRESS_STOP             _IO('C', 0x33)
 #define SNDRV_COMPRESS_DRAIN            _IO('C', 0x34)
+#define SNDRV_COMPRESS_NEXT_TRACK       _IO('C', 0x35)
+#define SNDRV_COMPRESS_PARTIAL_DRAIN    _IO('C', 0x36)
 /*
  * TODO
  * 1. add mmap support
  *
  */
 #define SND_COMPR_TRIGGER_DRAIN 7 /*FIXME move this to pcm.h */
+#define SND_COMPR_TRIGGER_NEXT_TRACK 8
+#define SND_COMPR_TRIGGER_PARTIAL_DRAIN 9
 #endif