demux/codec_tags: support more WAVEFORMATEXTENSIBLE tags

This patch adds support for two extra WAVEFORMATEXTENSIBLE GUID tags
that can appear inside RIFF headers. It also adds support for extra
codec IDs that may appear as their own unique wSubFormats inside RIFF
headers, such as ATRAC9 inside matroska, as one example.

Fixes #10757.

1 files changed, 78 insertions, 8 deletions

diff --git a/demux/codec_tags.c b/demux/codec_tags.c
index 8f8c97ec38..5cf7132d3a 100644
--- a/demux/codec_tags.c
+++ b/demux/codec_tags.c
@@ -44,15 +44,69 @@ static const char *lookup_tag(int type, uint32_t tag)
     return id == AV_CODEC_ID_NONE ? NULL : mp_codec_from_av_codec_id(id);
 }
 
-// Corresponds to WMMEDIASUBTYPE_Base.
-static const unsigned char guid_ext_base[16] =
+
+/* 
+ * As seen in the following page:
+ * 
+ * https://web.archive.org/web/20220406060153/
+ * http://dream.cs.bath.ac.uk/researchdev/wave-ex/bformat.html
+ * 
+ * Note that the GUID struct in the above citation has its
+ * integers encoded in little-endian format, which means that
+ * the unsigned short and unsigned long entries need to be
+ * byte-flipped for this encoding.
+ * 
+ * In theory only the first element of this array should be used,
+ * however some encoders incorrectly encoded the GUID byte-for-byte
+ * and thus the second one exists as a fallback.
+ */
+static const unsigned char guid_ext_base[][16] = {
+    // MEDIASUBTYPE_BASE_GUID
     {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00,
-     0x80, 0x00, 0x00, 0xAA, 0x00, 0x38, 0x9B, 0x71};
+     0x80, 0x00, 0x00, 0xAA, 0x00, 0x38, 0x9B, 0x71},
+     // SUBTYPE_AMBISONIC_B_FORMAT_PCM
+    {0x01, 0x00, 0x00, 0x00, 0x21, 0x07, 0xD3, 0x11,
+     0x86, 0x44, 0xC8, 0xC1, 0xCA, 0x00, 0x00, 0x00}
+};
+
+struct mp_waveformatex_guid {
+    const char *codec;
+    const unsigned char guid[16];
+};
+
+static const struct mp_waveformatex_guid guid_ext_other[] = {
+    {"ac3",
+        {0x2C, 0x80, 0x6D, 0xE0, 0x46, 0xDB, 0xCF, 0x11,
+         0xB4, 0xD1, 0x00, 0x80, 0x5F, 0x6C, 0xBB, 0xEA}},
+    {"adpcm_agm",
+        {0x82, 0xEC, 0x1F, 0x6A, 0xCA, 0xDB, 0x19, 0x45,
+         0xBD, 0xE7, 0x56, 0xD3, 0xB3, 0xEF, 0x98, 0x1D}},
+    {"atrac3p",
+        {0xBF, 0xAA, 0x23, 0xE9, 0x58, 0xCB, 0x71, 0x44,
+         0xA1, 0x19, 0xFF, 0xFA, 0x01, 0xE4, 0xCE, 0x62}},
+    {"atrac9",
+        {0xD2, 0x42, 0xE1, 0x47, 0xBA, 0x36, 0x8D, 0x4D,
+         0x88, 0xFC, 0x61, 0x65, 0x4F, 0x8C, 0x83, 0x6C}},
+    {"dfpwm",
+        {0x3A, 0xC1, 0xFA, 0x38, 0x81, 0x1D, 0x43, 0x61,
+         0xA4, 0x0D, 0xCE, 0x53, 0xCA, 0x60, 0x7C, 0xD1}},
+    {"eac3",
+        {0xAF, 0x87, 0xFB, 0xA7, 0x02, 0x2D, 0xFB, 0x42,
+         0xA4, 0xD4, 0x05, 0xCD, 0x93, 0x84, 0x3B, 0xDD}},
+    {"mp2",
+        {0x2B, 0x80, 0x6D, 0xE0, 0x46, 0xDB, 0xCF, 0x11,
+         0xB4, 0xD1, 0x00, 0x80, 0x5F, 0x6C, 0xBB, 0xEA}}
+};
 
 static void map_audio_pcm_tag(struct mp_codec_params *c)
 {
     // MS PCM, Extended
     if (c->codec_tag == 0xfffe && c->extradata_size >= 22) {
+        // WAVEFORMATEXTENSIBLE.wBitsPerSample
+        int bits_per_sample = AV_RL16(c->extradata);
+        if (bits_per_sample)
+            c->bits_per_coded_sample = bits_per_sample;
+
         // WAVEFORMATEXTENSIBLE.dwChannelMask
         uint64_t chmask = AV_RL32(c->extradata + 2);
         struct mp_chmap chmap;
@@ -62,9 +116,23 @@ static void map_audio_pcm_tag(struct mp_codec_params *c)
 
         // WAVEFORMATEXTENSIBLE.SubFormat
         unsigned char *subformat = c->extradata + 6;
-        if (memcmp(subformat + 4, guid_ext_base + 4, 12) == 0) {
-            c->codec_tag = AV_RL32(subformat);
-            c->codec = lookup_tag(c->type, c->codec_tag);
+        for (int i = 0; i < MP_ARRAY_SIZE(guid_ext_base); i++) {
+            if (memcmp(subformat + 4, guid_ext_base[i] + 4, 12) == 0) {
+                c->codec_tag = AV_RL32(subformat);
+                c->codec = lookup_tag(c->type, c->codec_tag);
+                break;
+            }
+        }
+
+        // extra subformat, not a base one
+        if (c->codec_tag == 0xfffe) {
+            for (int i = 0; i < MP_ARRAY_SIZE(guid_ext_other); i++) {
+                if (memcmp(subformat, &guid_ext_other[i].guid, 16) == 0) {
+                    c->codec = guid_ext_other[i].codec;
+                    c->codec_tag = mp_codec_to_av_codec_id(c->codec);
+                    break;
+                }
+            }
         }
 
         // Compressed formats might use this.
@@ -73,6 +141,9 @@ static void map_audio_pcm_tag(struct mp_codec_params *c)
     }
 
     int bits = c->bits_per_coded_sample;
+    if (!bits)
+        return;
+
     int bytes = (bits + 7) / 8;
     switch (c->codec_tag) {
     case 0x0:       // Microsoft PCM
@@ -89,8 +160,7 @@ static void map_audio_pcm_tag(struct mp_codec_params *c)
 void mp_set_codec_from_tag(struct mp_codec_params *c)
 {
     c->codec = lookup_tag(c->type, c->codec_tag);
-
-    if (c->type == STREAM_AUDIO && c->bits_per_coded_sample)
+    if (c->type == STREAM_AUDIO)
         map_audio_pcm_tag(c);
 }