oss4: also accept formats not natively supported

Also accept formats that are not natively supported by the
hardware, OSS4 can convert them internally. List the native
formats first in the caps though, to express our preference
for the native formats. We need this in order to support the
case properly where the audio hardware supports only e.g.
little endian PCM, but the host is big endian, since many
audio elements only support native endianness and make the
reasonable assumption that any audiosink will be able to
handle audio in native endianness.

Based on patch by Jerry Tan <jerry.tan@sun.com>

Fixes #614317.

diff --git a/sys/oss4/oss4-audio.c b/sys/oss4/oss4-audio.c
index 297ea7ff3ea4575b885975571291d575a46c0790..45a1ecc627722be1e45a595ada489f843c379538 100644 (file)
--- a/sys/oss4/oss4-audio.c
+++ b/sys/oss4/oss4-audio.c
@@ -73,6 +73,16 @@ static const struct
   GST_U8, AFMT_U8, "audio/x-raw-int", 8, 8, 0, FALSE}
 };
 
+/* formats we assume the OSS4 layer can always handle and convert internally */
+#define CONVERTIBLE_FORMATS (   \
+    AFMT_MU_LAW | AFMT_A_LAW |  \
+    AFMT_S32_LE | AFMT_S32_BE | \
+    AFMT_S24_LE | AFMT_S24_BE | \
+    AFMT_S24_PACKED |           \
+    AFMT_S16_LE | AFMT_S16_BE | \
+    AFMT_U16_LE | AFMT_U16_BE | \
+    AFMT_S8 | AFMT_U8 )
+
 static gboolean
 gst_oss4_append_format_to_caps (gint fmt, GstCaps * caps)
 {
@@ -411,6 +421,7 @@ gst_oss4_audio_probe_caps (GstObject * obj, int fd)
   oss_audioinfo ai = { 0, };
   gboolean output;
   GstCaps *caps;
+  int nonnative_formats = 0;
   int formats, i;
 
   output = GST_IS_OSS4_SINK (obj);
@@ -427,9 +438,22 @@ gst_oss4_audio_probe_caps (GstObject * obj, int fd)
 
   caps = gst_caps_new_empty ();
 
+  /* first list all the formats natively supported */
   for (i = 0; i < G_N_ELEMENTS (fmt_map); ++i) {
     if ((formats & fmt_map[i].oss_fmt)) {
       gst_oss4_append_format_to_caps (fmt_map[i].oss_fmt, caps);
+    } else if ((fmt_map[i].oss_fmt & CONVERTIBLE_FORMATS)) {
+      nonnative_formats |= fmt_map[i].oss_fmt;
+    }
+  }
+
+  GST_LOG_OBJECT (obj, "adding non-native %s formats : 0x%08x",
+      (output) ? "out" : "in", nonnative_formats);
+
+  /* now append non-native formats for which conversion would be needed */
+  for (i = 0; i < G_N_ELEMENTS (fmt_map); ++i) {
+    if ((nonnative_formats & fmt_map[i].oss_fmt)) {
+      gst_oss4_append_format_to_caps (fmt_map[i].oss_fmt, caps);
     }
   }