gst-libs/gst/audio/gstbaseaudiosink.c: Report the latency with the new seglatency parameter.

Original commit message from CVS:
* gst-libs/gst/audio/gstbaseaudiosink.c:
(gst_base_audio_sink_query):
Report the latency with the new seglatency parameter.
* gst-libs/gst/audio/gstringbuffer.c:
(gst_ring_buffer_debug_spec_buff), (gst_ring_buffer_parse_caps),
(gst_ring_buffer_acquire):
* gst-libs/gst/audio/gstringbuffer.h:
Add new field to the ringbufferspec to specify the expected latency
between the underlying device read/write pointer, this is needed
when writing sinks that sit a little closer to the hardware.
Add some more docs for other fields.

ChangeLog

@@ -1,3 +1,18 @@
+2008-05-07  Wim Taymans  <wim.taymans@collabora.co.uk>
+
+	* gst-libs/gst/audio/gstbaseaudiosink.c:
+	(gst_base_audio_sink_query):
+	Report the latency with the new seglatency parameter.
+
+	* gst-libs/gst/audio/gstringbuffer.c:
+	(gst_ring_buffer_debug_spec_buff), (gst_ring_buffer_parse_caps),
+	(gst_ring_buffer_acquire):
+	* gst-libs/gst/audio/gstringbuffer.h:
+	Add new field to the ringbufferspec to specify the expected latency
+	between the underlying device read/write pointer, this is needed
+	when writing sinks that sit a little closer to the hardware.
+	Add some more docs for other fields.
+
 2008-05-06  Sebastian Dröge  <slomo@circular-chaos.org>
 
 	* gst/volume/gstvolume.c: (volume_transform_ip):

gst-libs/gst/audio/gstbaseaudiosink.c

@@ -333,7 +333,7 @@ gst_base_audio_sink_query (GstElement * element, GstQuery * query)
           basesink->priv->us_latency = min_l;
 
           min_latency =
-              gst_util_uint64_scale_int (spec->segtotal * spec->segsize,
+              gst_util_uint64_scale_int (spec->seglatency * spec->segsize,
               GST_SECOND, spec->rate * spec->bytes_per_sample);
 
           /* we cannot go lower than the buffer size and the min peer latency */

gst-libs/gst/audio/gstringbuffer.c

@@ -258,6 +258,7 @@ gst_ring_buffer_debug_spec_buff (GstRingBufferSpec * spec)
   GST_DEBUG ("acquire ringbuffer: latency time: %" G_GINT64_FORMAT " usec",
       spec->latency_time);
   GST_DEBUG ("acquire ringbuffer: total segments: %d", spec->segtotal);
+  GST_DEBUG ("acquire ringbuffer: latency segments: %d", spec->seglatency);
   GST_DEBUG ("acquire ringbuffer: segment size: %d bytes = %d samples",
       spec->segsize, spec->segsize / spec->bytes_per_sample);
   GST_DEBUG ("acquire ringbuffer: buffer size: %d bytes = %d samples",
@@ -414,6 +415,9 @@ gst_ring_buffer_parse_caps (GstRingBufferSpec * spec, GstCaps * caps)
   spec->segsize -= spec->segsize % spec->bytes_per_sample;
 
   spec->segtotal = spec->buffer_time / spec->latency_time;
+  /* leave the latency undefined now, implementations can change it but if it's
+   * not changed, we assume the same value as segtotal */
+  spec->seglatency = -1;
 
   gst_ring_buffer_debug_spec_caps (spec);
   gst_ring_buffer_debug_spec_buff (spec);
@@ -649,6 +653,11 @@ gst_ring_buffer_acquire (GstRingBuffer * buf, GstRingBufferSpec * spec)
   if (G_UNLIKELY ((bps = buf->spec.bytes_per_sample) == 0))
     goto invalid_bps;
 
+  /* if the seglatency was overwritten with something else than -1, use it, else
+   * assume segtotal as the latency */
+  if (buf->spec.seglatency == -1)
+    buf->spec.seglatency = buf->spec.segtotal;
+
   segsize = buf->spec.segsize;
 
   buf->samples_per_seg = segsize / bps;

gst-libs/gst/audio/gstringbuffer.h

@@ -200,17 +200,30 @@ struct _GstRingBufferSpec
   gint      rate;
   gint      channels;
   
-  guint64  latency_time;        /* the required/actual latency time */
-  guint64  buffer_time;         /* the required/actual time of the buffer */
-  gint     segsize;             /* size of one buffer segment in bytes */
-  gint     segtotal;            /* total number of segments */
-
+  guint64  latency_time;        /* the required/actual latency time, this is the
+				 * actual the size of one segment and the
+				 * minimum possible latency we can achieve. */
+  guint64  buffer_time;         /* the required/actual time of the buffer, this is
+				 * the total size of the buffer and maximum
+				 * latency we can compensate for. */
+  gint     segsize;             /* size of one buffer segment in bytes, this value
+				 * should be chosen to match latency_time as
+				 * well as possible. */
+  gint     segtotal;            /* total number of segments, this value is the
+				 * number of segments of @segsize and should be
+				 * chosen so that it matches buffer_time as
+				 * close as possible. */
   /* out */
   gint     bytes_per_sample;    /* number of bytes of one sample */
   guint8   silence_sample[32];  /* bytes representing silence */
 
+  /* ABI added 0.10.20 */
+  gint     seglatency;          /* number of segments queued in the lower
+				 * level device, defaults to segtotal. */
+
   /*< private >*/
-  gpointer _gst_reserved[GST_PADDING];
+  /* gpointer _gst_reserved[GST_PADDING]; */
+  guint8 _gst_reserved[(sizeof (gpointer) * GST_PADDING) - sizeof (gint)];
 };
 
 #define GST_RING_BUFFER_GET_COND(buf) (((GstRingBuffer *)buf)->cond)