[Fix] Support to wave sound file under linux

Some wave file had a 'fact' chunk in header's data.
This is specified for non-PCM format but some PCM wave sound file could have one.
These kind of file are played well by System.Media.SoundPlay on win32 system but no
sound is played at all on unix system because the 'data' chunk is not found. This
patch adds support for wave file which have this optional 'fact' chunk in header's data.
It's also read chunk data according to the chunk size.

Signed-off-by: Florent Valette <florent.valette@gmail.com>

diff --git a/mcs/class/System/System.Media/AudioData.cs b/mcs/class/System/System.Media/AudioData.cs
index 552fc0d92d32d1bed23790b1627dfa375863f8f0..f81ec6fe76c06485bdbe23544ee9b96b810a4ccd 100644 (file)
--- a/mcs/class/System/System.Media/AudioData.cs
+++ b/mcs/class/System/System.Media/AudioData.cs
@@ -59,63 +59,99 @@ namespace Mono.Audio {
                ushort frame_divider;
                int sample_rate;
                int data_len = 0;
+               long data_offset = 0;
                AudioFormat format;
 
                public WavData (Stream data) {
                        stream = data;
-                       byte[] buffer = new byte [12+32];
-                       int c = stream.Read (buffer, 0, 12 + 32);
-                       if (c != (12 + 32) || 
-                                       buffer [0] != 'R' || buffer [1] != 'I' || buffer [2] != 'F' || buffer [3] != 'F' ||
-                                       buffer [8] != 'W' || buffer [9] != 'A' || buffer [10] != 'V' || buffer [11] != 'E') {
+                       byte[] buffer = new byte [12 + 32];
+                       int idx;
+                       
+                       // Read Chunk ID + Format
+                       int c = stream.Read (buffer, 0, 12);
+                       if (c != 12 ||
+                               buffer [0] != 'R' || buffer [1] != 'I' || buffer [2] != 'F' || buffer [3] != 'F' ||
+                               buffer [8] != 'W' || buffer [9] != 'A' || buffer [10] != 'V' || buffer [11] != 'E') {
                                throw new Exception ("incorrect format" + c);
                        }
-                       if (buffer [12] != 'f' || buffer [13] != 'm' || buffer [14] != 't' || buffer [15] != ' ') {
+
+                       // Read SubChunk 1 ID + Size => Must be 'fmt ' !
+                       c = stream.Read (buffer, 0, 8);
+                       if (c == 8 && buffer [0] == 'f' && buffer [1] == 'm' && buffer [2] == 't' && buffer [3] == ' ') {
+                               int sub_chunk_1_size = buffer [4];
+                               sub_chunk_1_size |= buffer [5] << 8;
+                               sub_chunk_1_size |= buffer [6] << 16;
+                               sub_chunk_1_size |= buffer [7] << 24;
+
+                               // Read SubChunk 1 Data
+                               c = stream.Read (buffer, 0, sub_chunk_1_size);
+                               if (sub_chunk_1_size == c)
+                               {
+                                       idx = 0;
+                                       int compression = buffer [idx++] | (buffer [idx++] << 8);
+                                       if (compression != 1)
+                                               throw new Exception ("incorrect format (not PCM)");
+                                       channels = (short)(buffer [idx++] | (buffer [idx++] << 8));
+                                       sample_rate = buffer [idx++];
+                                       sample_rate |= buffer [idx++] << 8;
+                                       sample_rate |= buffer [idx++] << 16;
+                                       sample_rate |= buffer [idx++] << 24;
+                                       int byte_rate = buffer [idx++];
+                                       byte_rate |= buffer [idx++] << 8;
+                                       byte_rate |= buffer [idx++] << 16;
+                                       byte_rate |= buffer [idx++] << 24;
+                                       int block_align = buffer [idx++] | (buffer [idx++] << 8);
+                                       int sign_bits = buffer [idx++] | (buffer [idx++] << 8);
+
+                                       switch (sign_bits) {
+                                       case 8:
+                                               frame_divider = 1;
+                                               format = AudioFormat.U8; break;
+                                       case 16:
+                                               frame_divider = 2;
+                                               format = AudioFormat.S16_LE; break;
+                                       default:
+                                               throw new Exception ("bits per sample");
+                                       }
+
+                               } else {
+                                       throw new Exception ("Error: Can't Read "+sub_chunk_1_size+" bytes from stream ("+c+" bytes read");
+                               }
+                       } else {
                                throw new Exception ("incorrect format (fmt)");
                        }
-                       int extra_size = buffer [16];
-                       extra_size |= buffer [17] << 8;
-                       extra_size |= buffer [18] << 16;
-                       extra_size |= buffer [19] << 24;
-                       int compression = buffer [20] | (buffer [21] << 8);
-                       if (compression != 1)
-                               throw new Exception ("incorrect format (not PCM)");
-                       channels = (short)(buffer [22] | (buffer [23] << 8));
-                       sample_rate = buffer [24];
-                       sample_rate |= buffer [25] << 8;
-                       sample_rate |= buffer [26] << 16;
-                       sample_rate |= buffer [27] << 24;
-                       int avg_bytes = buffer [28];
-                       avg_bytes |= buffer [29] << 8;
-                       avg_bytes |= buffer [30] << 16;
-                       avg_bytes |= buffer [31] << 24;
-                       //int block_align = buffer [32] | (buffer [33] << 8);
-                       int sign_bits = buffer [34] | (buffer [35] << 8);
-                       /*Console.WriteLine (extra_size);
-                       Console.WriteLine (compression);
-                       Console.WriteLine (channels);
-                       Console.WriteLine (sample_rate);
-                       Console.WriteLine (avg_bytes);
-                       Console.WriteLine (block_align);
-                       Console.WriteLine (sign_bits);*/
-                       if (buffer [36] != 'd' || buffer [37] != 'a' || buffer [38] != 't' || buffer [39] != 'a') {
-                               throw new Exception ("incorrect format (data)");
-                       }
-                       int sample_size = buffer [40];
-                       sample_size |= buffer [41] << 8;
-                       sample_size |= buffer [42] << 16;
-                       sample_size |= buffer [43] << 24;
-                       data_len = sample_size;
-                       //Console.WriteLine (sample_size);
-                       switch (sign_bits) {
-                       case 8:
-                               frame_divider = 1;
-                               format = AudioFormat.U8; break;
-                       case 16:
-                               frame_divider = 2;
-                               format = AudioFormat.S16_LE; break;
-                       default:
-                               throw new Exception ("bits per sample");
+
+                       // Read SubChunk 2 ID + Size => Could be 'fact' or 'data' !
+                       c = stream.Read (buffer, 0, 8);
+                       if (c == 8) {
+                               // If SubChunk 2 ID = fact
+                               if (buffer [0] == 'f' && buffer [1] == 'a' && buffer [2] == 'c' && buffer [3] == 't') {
+                                       // Read Data
+                                       int sub_chunk_2_size = buffer [4];
+                                       sub_chunk_2_size |= buffer [5] << 8;
+                                       sub_chunk_2_size |= buffer [6] << 16;
+                                       sub_chunk_2_size |= buffer [7] << 24;
+
+                                       c = stream.Read (buffer, 0, sub_chunk_2_size);
+
+                                       // Don't care about this data !
+
+                                       // If there is a fact Chunck, read the next subChunk Id and size (should be data !)
+                                       c = stream.Read (buffer, 0, 8);
+                               }
+
+                               if (buffer [0] == 'd' && buffer [1] == 'a' && buffer [2] == 't' && buffer [3] == 'a') {
+                                       // Read Data
+                                       int sub_chunk_2_size = buffer [4];
+                                       sub_chunk_2_size |= buffer [5] << 8;
+                                       sub_chunk_2_size |= buffer [6] << 16;
+                                       sub_chunk_2_size |= buffer [7] << 24;
+
+                                       data_len = sub_chunk_2_size;
+                                       data_offset = stream.Position;
+                               } else { 
+                                       throw new Exception ("incorrect format (data/fact chunck)");
+                               }
                        }
                }