From 7b39d853b88e4be03f2cfb346df3ad55ccae3377 Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <cehoyos@ag.or.at>
Date: Fri, 10 Apr 2015 12:35:02 +0200
Subject: [PATCH] lavf/flac: Autodetect raw flac files.

---
 libavformat/flacdec.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/libavformat/flacdec.c b/libavformat/flacdec.c
index 1a8dc19af3..4207fd2bf6 100644
--- a/libavformat/flacdec.c
+++ b/libavformat/flacdec.c
@@ -176,8 +176,26 @@ fail:
     return ret;
 }
 
+static int raw_flac_probe(AVProbeData *p)
+{
+    if ((p->buf[2] & 0xF0) == 0)    // blocksize code invalid
+        return 0;
+    if ((p->buf[2] & 0x0F) == 0x0F) // sample rate code invalid
+        return 0;
+    if ((p->buf[3] & 0xF0) >= FLAC_MAX_CHANNELS + FLAC_CHMODE_MID_SIDE << 4)
+        // channel mode invalid
+        return 0;
+    if ((p->buf[3] & 0x06) == 0x06) // bits per sample code invalid
+        return 0;
+    if ((p->buf[3] & 0x01) == 0x01) // reserved bit set
+        return 0;
+    return AVPROBE_SCORE_EXTENSION / 4 + 1;
+}
+
 static int flac_probe(AVProbeData *p)
 {
+    if ((AV_RB16(p->buf) & 0xFFFE) == 0xFFF8)
+        return raw_flac_probe(p);
     if (p->buf_size < 4 || memcmp(p->buf, "fLaC", 4))
         return 0;
     return AVPROBE_SCORE_EXTENSION;