Better support for 24-bit lpcm

First of all, it improves the qt demuxer, ensuring that 24-bit audio is
marked appropriately, and detecting little vs. big endian audio. It also
adjusts the buffer size when audio is 24-bit, ensuring that samples aren't
chopped in half (8192 does not divide evenly into 3 byte samples).

Secondly, in the lpcm decoder, the patch distinguishes between standard
24-bit lpcm (big and little endian) and special DVD-format 24-bit lpcm (see
http://wiki.multimedia.cx/index.php?title=PCM) and now handles both, instead
of only handling the DVD format.

The result is that xine now correctly plays all the 24-bit lpcm samples I
throw at it, whereas before only a few worked.

1 files changed, 45 insertions, 21 deletions

diff --git a/src/libxineadec/xine_lpcm_decoder.c b/src/libxineadec/xine_lpcm_decoder.c
index 6f4e71003..17db68550 100644
--- a/src/libxineadec/xine_lpcm_decoder.c
+++ b/src/libxineadec/xine_lpcm_decoder.c
@@ -94,6 +94,7 @@ static void lpcm_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) {
   int             stream_be;
   audio_buffer_t *audio_buffer;
   int             format_changed = 0;
+  int             special_dvd_audio = 0;
 
   /* Drop preview data */
   if (buf->decoder_flags & BUF_FLAG_PREVIEW)
@@ -116,7 +117,7 @@ static void lpcm_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) {
       switch ((buf->decoder_info[2] >> (24+6)) & 0x03) {
         case 1:  bits_per_sample = 16; break;
         case 2:  bits_per_sample = 20; break;
-        case 3:  bits_per_sample = 24; break;
+        case 3:  bits_per_sample = 24; special_dvd_audio = 1; break;
         default: bits_per_sample =  0; break;
       }
       switch ((buf->decoder_info[2] >> 16) & 0x0f) {
@@ -152,7 +153,7 @@ static void lpcm_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) {
       switch ((buf->decoder_info[2]>>6) & 3) {
         case 0: bits_per_sample = 16; break;
         case 1: bits_per_sample = 20; break;
-        case 2: bits_per_sample = 24; break;
+        case 2: bits_per_sample = 24; special_dvd_audio = 1; break;
       }
     }
 
@@ -270,35 +271,58 @@ static void lpcm_decode_data (audio_decoder_t *this_gen, buf_element_t *buf) {
     int n = buf_size;
 
     if ( stream_be ) {
-      while (n >= 12) {
+      if (special_dvd_audio)
+        while (n >= 12) {
+          if ( stream_be == this->cpu_be ) {
+            *d++ = s[0];
+            *d++ = s[1];
+            *d++ = s[2];
+            *d++ = s[3];
+            *d++ = s[4];
+            *d++ = s[5];
+            *d++ = s[6];
+            *d++ = s[7];
+          } else {
+            *d++ = s[1];
+            *d++ = s[0];
+            *d++ = s[3];
+            *d++ = s[2];
+            *d++ = s[5];
+            *d++ = s[4];
+            *d++ = s[7];
+            *d++ = s[6];
+          }
+          s += 12;
+          n -= 12;
+        }
+      else
+        while (n >= 3) {
+          if ( stream_be == this->cpu_be ) {
+            *d++ = s[0];
+            *d++ = s[1];
+          } else {
+            *d++ = s[1];
+            *d++ = s[0];
+          }
+          s += 3;
+          n -= 3;
+        }
+    } else {
+      while (n >= 3) {
         if ( stream_be == this->cpu_be ) {
-          *d++ = s[0];
           *d++ = s[1];
           *d++ = s[2];
-          *d++ = s[3];
-          *d++ = s[4];
-          *d++ = s[5];
-          *d++ = s[6];
-          *d++ = s[7];
         } else {
-          *d++ = s[1];
-          *d++ = s[0];
-          *d++ = s[3];
           *d++ = s[2];
-          *d++ = s[5];
-          *d++ = s[4];
-          *d++ = s[7];
-          *d++ = s[6];
+          *d++ = s[1];
         }
-	s += 12;
-	n -= 12;
+        s += 3;
+        n -= 3;
       }
-    } else {
-      xprintf(this->stream->xine, XINE_VERBOSITY_DEBUG, "lpcm_decoder: I don't know what should decode lpcm 24bit little endian byte stream");
     }
 
     if ( (d - (uint8_t*)audio_buffer->mem)/2*3 < buf_size )
-	xprintf(this->stream->xine, XINE_VERBOSITY_DEBUG, "lpcm_decoder: lost %i bytes\n", (int)(buf_size - (d - (uint8_t*)audio_buffer->mem))/2*3);
+	xprintf(this->stream->xine, XINE_VERBOSITY_DEBUG, "lpcm_decoder: lost %i bytes of %i in the buffer\n", (int)(buf_size - (d - (uint8_t*)audio_buffer->mem)/2*3), buf_size);
 
   } else {
     memcpy (audio_buffer->mem, sample_buffer, buf_size);