Merge pull request #1034 from wader/wav-fmt-cbsize

wav: Decode fmt chunk cb_size and bytes
wader · Nov 21, 2024 · 8f9e84d · 8f9e84d
2 parents 95819c9 + 4a9f65d
commit 8f9e84d
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Showing 3 changed files with 28 additions and 5 deletions.
diff --git a/format/riff/testdata/fmt_cb_size_unknown.wav b/format/riff/testdata/fmt_cb_size_unknown.wav
diff --git a/format/riff/testdata/fmt_cb_size_unknown.wav.fqtest b/format/riff/testdata/fmt_cb_size_unknown.wav.fqtest
@@ -0,0 +1,17 @@
+$ fq dv fmt_cb_size_unknown.wav
+    |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|0123456789abcdef|.{}: fmt_cb_size_unknown.wav (wav) 0x0-0x28 (40)
+0x00|52 49 46 46                                    |RIFF            |  id: "RIFF" 0x0-0x4 (4)
+0x00|            20 00 00 00                        |     ...        |  size: 32 0x4-0x8 (4)
+0x00|                        57 41 56 45            |        WAVE    |  format: "WAVE" (valid) 0x8-0xc (4)
+    |                                               |                |  chunks[0:1]: 0xc-0x28 (28)
+    |                                               |                |    [0]{}: chunk 0xc-0x28 (28)
+0x00|                                    66 6d 74 20|            fmt |      id: "fmt" 0xc-0x10 (4)
+0x10|14 00 00 00                                    |....            |      size: 20 0x10-0x14 (4)
+0x10|            01 00                              |    ..          |      audio_format: "pcm_s16le" (1) 0x14-0x16 (2)
+0x10|                  02 00                        |      ..        |      num_channels: 2 0x16-0x18 (2)
+0x10|                        44 ac 00 00            |        D...    |      sample_rate: 44100 0x18-0x1c (4)
+0x10|                                    20 62 05 00|             b..|      byte_rate: 352800 0x1c-0x20 (4)
+0x20|08 00                                          |..              |      block_align: 8 0x20-0x22 (2)
+0x20|      20 00                                    |   .            |      bits_per_sample: 32 0x22-0x24 (2)
+0x20|            02 00                              |    ..          |      cb_size: 2 0x24-0x26 (2)
+0x20|                  01 00|                       |      ..|       |      unknown: raw bits 0x26-0x28 (2)
diff --git a/format/riff/wav.go b/format/riff/wav.go
@@ -94,12 +94,18 @@ func wavDecode(d *decode.D) any {
 				d.FieldU16("block_align")
 				d.FieldU16("bits_per_sample")
 
-				if audioFormat == formatExtensible && d.BitsLeft() > 0 {
-					d.FieldU16("extension_size")
-					d.FieldU16("valid_bits_per_sample")
-					d.FieldU32("channel_mask")
-					d.FieldRawLen("sub_format", 16*8, subFormatNames)
+				if d.BitsLeft() > 0 {
+					if audioFormat == formatExtensible {
+						d.FieldU16("extension_size")
+						d.FieldU16("valid_bits_per_sample")
+						d.FieldU32("channel_mask")
+						d.FieldRawLen("sub_format", 16*8, subFormatNames)
+					} else {
+						cbSize := d.FieldU16("cb_size")
+						d.FieldRawLen("unknown", int64(cbSize)*8)
+					}
 				}
+
 				return false, nil
 
 			case "data":