Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

22 files changed, 791 insertions, 0 deletions

diff --git a/toolkit/components/mediasniffer/components.conf b/toolkit/components/mediasniffer/components.conf
new file mode 100644
index 0000000000..ba3c89b942
--- /dev/null
+++ b/toolkit/components/mediasniffer/components.conf
@@ -0,0 +1,20 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+Classes = [
+    {
+        'cid': '{3fdd6c28-5b87-4e3e-8b57-8e83c23c1a6d}',
+        'contract_ids': ['@mozilla.org/media/sniffer;1'],
+        'type': 'nsMediaSniffer',
+        'headers': ['nsMediaSniffer.h'],
+        'categories': {
+            'content-sniffing-services': '@mozilla.org/media/sniffer;1',
+            'net-content-sniffers': '@mozilla.org/media/sniffer;1',
+            'orb-content-sniffers': '@mozilla.org/media/sniffer;1',
+            'net-and-orb-content-sniffers': '@mozilla.org/media/sniffer;1',
+        },
+    },
+]
diff --git a/toolkit/components/mediasniffer/moz.build b/toolkit/components/mediasniffer/moz.build
new file mode 100644
index 0000000000..783b4555da
--- /dev/null
+++ b/toolkit/components/mediasniffer/moz.build
@@ -0,0 +1,33 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPCSHELL_TESTS_MANIFESTS += ["test/unit/xpcshell.ini"]
+
+EXPORTS += [
+    "nsMediaSniffer.h",
+]
+
+UNIFIED_SOURCES += [
+    "mp3sniff.c",
+    "nsMediaSniffer.cpp",
+]
+
+XPCOM_MANIFESTS += [
+    "components.conf",
+]
+
+FINAL_LIBRARY = "xul"
+
+with Files("**"):
+    BUG_COMPONENT = ("Core", "Audio/Video")
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+LOCAL_INCLUDES += [
+    # For nsHttpChannel.h
+    "/netwerk/base",
+    "/netwerk/protocol/http",
+]
diff --git a/toolkit/components/mediasniffer/mp3sniff.c b/toolkit/components/mediasniffer/mp3sniff.c
new file mode 100644
index 0000000000..cb1e2fdc1d
--- /dev/null
+++ b/toolkit/components/mediasniffer/mp3sniff.c
@@ -0,0 +1,156 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* MPEG format parsing */
+
+#include "mp3sniff.h"
+
+/* Maximum packet size is 320 kbits/s * 144 / 32 kHz + 1 padding byte */
+#define MP3_MAX_SIZE 1441
+
+typedef struct {
+  int version;
+  int layer;
+  int errp;
+  int bitrate;
+  int freq;
+  int pad;
+  int priv;
+  int mode;
+  int modex;
+  int copyright;
+  int original;
+  int emphasis;
+} mp3_header;
+
+/* Parse the 4-byte header in p and fill in the header struct. */
+static void mp3_parse(const uint8_t* p, mp3_header* header) {
+  const int bitrates[2][16] = {
+      /* MPEG version 1 layer 3 bitrates. */
+      {0, 32000, 40000, 48000, 56000, 64000, 80000, 96000, 112000, 128000,
+       160000, 192000, 224000, 256000, 320000, 0},
+      /* MPEG Version 2 and 2.5 layer 3 bitrates */
+      {0, 8000, 16000, 24000, 32000, 40000, 48000, 56000, 64000, 80000, 96000,
+       112000, 128000, 144000, 160000, 0}};
+  const int samplerates[4] = {44100, 48000, 32000, 0};
+
+  header->version = (p[1] & 0x18) >> 3;
+  header->layer = 4 - ((p[1] & 0x06) >> 1);
+  header->errp = (p[1] & 0x01);
+
+  header->bitrate = bitrates[(header->version & 1) ? 0 : 1][(p[2] & 0xf0) >> 4];
+  header->freq = samplerates[(p[2] & 0x0c) >> 2];
+  if (header->version == 2)
+    header->freq >>= 1;
+  else if (header->version == 0)
+    header->freq >>= 2;
+  header->pad = (p[2] & 0x02) >> 1;
+  header->priv = (p[2] & 0x01);
+
+  header->mode = (p[3] & 0xc0) >> 6;
+  header->modex = (p[3] & 0x30) >> 4;
+  header->copyright = (p[3] & 0x08) >> 3;
+  header->original = (p[3] & 0x04) >> 2;
+  header->emphasis = (p[3] & 0x03);
+}
+
+/* calculate the size of an mp3 frame from its header */
+static int mp3_framesize(mp3_header* header) {
+  int size;
+  int scale;
+
+  if ((header->version & 1) == 0)
+    scale = 72;
+  else
+    scale = 144;
+  size = header->bitrate * scale / header->freq;
+  if (header->pad) size += 1;
+
+  return size;
+}
+
+static int is_mp3(const uint8_t* p, long length) {
+  /* Do we have enough room to see a 4 byte header? */
+  if (length < 4) return 0;
+  /* Do we have a sync pattern? */
+  if (p[0] == 0xff && (p[1] & 0xe0) == 0xe0) {
+    /* Do we have any illegal field values? */
+    if (((p[1] & 0x06) >> 1) == 0) return 0;  /* No layer 4 */
+    if (((p[2] & 0xf0) >> 4) == 15) return 0; /* Bitrate can't be 1111 */
+    if (((p[2] & 0x0c) >> 2) == 3) return 0;  /* Samplerate can't be 11 */
+    /* Looks like a header. */
+    if ((4 - ((p[1] & 0x06) >> 1)) != 3) return 0; /* Only want level 3 */
+    return 1;
+  }
+  return 0;
+}
+
+/* Identify an ID3 tag based on its header. */
+/* http://id3.org/id3v2.4.0-structure */
+static int is_id3(const uint8_t* p, long length) {
+  /* Do we have enough room to see the header? */
+  if (length < 10) return 0;
+  /* Do we have a sync pattern? */
+  if (p[0] == 'I' && p[1] == 'D' && p[2] == '3') {
+    if (p[3] == 0xff || p[4] == 0xff) return 0; /* Illegal version. */
+    if (p[6] & 0x80 || p[7] & 0x80 || p[8] & 0x80)
+      return 0; /* Bad length encoding. */
+    /* Looks like an id3 header. */
+    return 1;
+  }
+  return 0;
+}
+
+/* Calculate the size of an id3 tag structure from its header. */
+static int id3_framesize(const uint8_t* p, long length) {
+  int size;
+
+  /* Header is 10 bytes. */
+  if (length < 10) {
+    return 0;
+  }
+  /* Frame is header plus declared size. */
+  size = 10 + (p[9] | (p[8] << 7) | (p[7] << 14) | (p[6] << 21));
+
+  return size;
+}
+
+int mp3_sniff(const uint8_t* buf, long length) {
+  mp3_header header;
+  const uint8_t* p;
+  long skip;
+  long avail;
+
+  p = buf;
+  avail = length;
+  while (avail >= 4) {
+    if (is_id3(p, avail)) {
+      /* Skip over any id3 tags */
+      skip = id3_framesize(p, avail);
+      p += skip;
+      avail -= skip;
+    } else if (is_mp3(p, avail)) {
+      mp3_parse(p, &header);
+      skip = mp3_framesize(&header);
+      if (skip < 4 || skip + 4 >= avail) {
+        return 0;
+      }
+      p += skip;
+      avail -= skip;
+      /* Check for a second header at the expected offset. */
+      if (is_mp3(p, avail)) {
+        /* Looks like mp3. */
+        return 1;
+      } else {
+        /* No second header. Not mp3. */
+        return 0;
+      }
+    } else {
+      /* No id3 tag or mp3 header. Not mp3. */
+      return 0;
+    }
+  }
+
+  return 0;
+}
diff --git a/toolkit/components/mediasniffer/mp3sniff.h b/toolkit/components/mediasniffer/mp3sniff.h
new file mode 100644
index 0000000000..b189db1873
--- /dev/null
+++ b/toolkit/components/mediasniffer/mp3sniff.h
@@ -0,0 +1,15 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+int mp3_sniff(const uint8_t* buf, long length);
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/toolkit/components/mediasniffer/nsMediaSniffer.cpp b/toolkit/components/mediasniffer/nsMediaSniffer.cpp
new file mode 100644
index 0000000000..b6752cb438
--- /dev/null
+++ b/toolkit/components/mediasniffer/nsMediaSniffer.cpp
@@ -0,0 +1,245 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 tw=80 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ADTSDemuxer.h"
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/ModuleUtils.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/StaticPrefs_media.h"
+#include "mozilla/Telemetry.h"
+#include "mp3sniff.h"
+#include "nestegg/nestegg.h"
+#include "nsHttpChannel.h"
+#include "nsIClassInfoImpl.h"
+#include "nsIChannel.h"
+#include "nsMediaSniffer.h"
+#include "nsMimeTypes.h"
+#include "nsQueryObject.h"
+#include "nsString.h"
+
+#include <algorithm>
+
+// The minimum number of bytes that are needed to attempt to sniff an mp4 file.
+static const unsigned MP4_MIN_BYTES_COUNT = 12;
+// The maximum number of bytes to consider when attempting to sniff a file.
+static const uint32_t MAX_BYTES_SNIFFED = 512;
+// The maximum number of bytes to consider when attempting to sniff for a mp3
+// bitstream.
+// This is 320kbps * 144 / 32kHz + 1 padding byte + 4 bytes of capture pattern.
+static const uint32_t MAX_BYTES_SNIFFED_MP3 = 320 * 144 / 32 + 1 + 4;
+// Multi-channel low sample-rate AAC packets can be huge, have a higher maximum
+// size.
+static const uint32_t MAX_BYTES_SNIFFED_ADTS = 8096;
+
+NS_IMPL_ISUPPORTS(nsMediaSniffer, nsIContentSniffer)
+
+nsMediaSnifferEntry nsMediaSniffer::sSnifferEntries[] = {
+    // The string OggS, followed by the null byte.
+    PATTERN_ENTRY("\xFF\xFF\xFF\xFF\xFF", "OggS", APPLICATION_OGG),
+    // The string RIFF, followed by four bytes, followed by the string WAVE,
+    // followed by 8 bytes, followed by 0x0055, the codec identifier for mp3 in
+    // a RIFF container. This entry MUST be before the next one, which is
+    // assumed to be a WAV file containing PCM data.
+    PATTERN_ENTRY("\xFF\xFF\xFF\xFF"
+                  "\x00\x00\x00\x00"
+                  "\xFF\xFF\xFF\xFF"
+                  "\x00\x00\x00\x00"
+                  "\x00\x00\x00\x00"
+                  "\xFF\xFF",
+                  "RIFF"
+                  "\x00\x00\x00\x00"
+                  "WAVE"
+                  "\x00\x00\x00\x00"
+                  "\x00\x00\x00\x00"
+                  "\x55\x00",
+                  AUDIO_MP3),
+    // The string RIFF, followed by four bytes, followed by the string WAVE
+    PATTERN_ENTRY("\xFF\xFF\xFF\xFF\x00\x00\x00\x00\xFF\xFF\xFF\xFF",
+                  "RIFF\x00\x00\x00\x00WAVE", AUDIO_WAV),
+    // mp3 with ID3 tags, the string "ID3".
+    PATTERN_ENTRY("\xFF\xFF\xFF", "ID3", AUDIO_MP3),
+    // FLAC with standard header
+    PATTERN_ENTRY("\xFF\xFF\xFF\xFF", "fLaC", AUDIO_FLAC),
+    PATTERN_ENTRY("\xFF\xFF\xFF\xFF\xFF\xFF\xFF", "#EXTM3U",
+                  APPLICATION_MPEGURL)};
+
+using PatternLabel = mozilla::Telemetry::LABELS_MEDIA_SNIFFER_MP4_BRAND_PATTERN;
+
+struct nsMediaSnifferFtypEntry : nsMediaSnifferEntry {
+  nsMediaSnifferFtypEntry(nsMediaSnifferEntry aBase, const PatternLabel aLabel)
+      : nsMediaSnifferEntry(aBase), mLabel(aLabel) {}
+  PatternLabel mLabel;
+};
+
+// For a complete list of file types, see http://www.ftyps.com/index.html
+nsMediaSnifferFtypEntry sFtypEntries[] = {
+    {PATTERN_ENTRY("\xFF\xFF\xFF", "mp4", VIDEO_MP4),
+     PatternLabel::ftyp_mp4},  // Could be mp41 or mp42.
+    {PATTERN_ENTRY("\xFF\xFF\xFF", "avc", VIDEO_MP4),
+     PatternLabel::ftyp_avc},  // Could be avc1, avc2, ...
+    {PATTERN_ENTRY("\xFF\xFF\xFF\xFF", "3gp4", VIDEO_MP4),
+     PatternLabel::ftyp_3gp4},  // 3gp4 is based on MP4
+    {PATTERN_ENTRY("\xFF\xFF\xFF", "3gp", VIDEO_3GPP),
+     PatternLabel::ftyp_3gp},  // Could be 3gp5, ...
+    {PATTERN_ENTRY("\xFF\xFF\xFF", "M4V", VIDEO_MP4), PatternLabel::ftyp_M4V},
+    {PATTERN_ENTRY("\xFF\xFF\xFF", "M4A", AUDIO_MP4), PatternLabel::ftyp_M4A},
+    {PATTERN_ENTRY("\xFF\xFF\xFF", "M4P", AUDIO_MP4), PatternLabel::ftyp_M4P},
+    {PATTERN_ENTRY("\xFF\xFF", "qt", VIDEO_QUICKTIME), PatternLabel::ftyp_qt},
+    {PATTERN_ENTRY("\xFF\xFF\xFF", "crx", APPLICATION_OCTET_STREAM),
+     PatternLabel::ftyp_crx},
+    {PATTERN_ENTRY("\xFF\xFF\xFF", "iso", VIDEO_MP4),
+     PatternLabel::ftyp_iso},  // Could be isom or iso2.
+    {PATTERN_ENTRY("\xFF\xFF\xFF\xFF", "mmp4", VIDEO_MP4),
+     PatternLabel::ftyp_mmp4},
+    {PATTERN_ENTRY("\xFF\xFF\xFF\xFF", "avif", IMAGE_AVIF),
+     PatternLabel::ftyp_avif},
+};
+
+static bool MatchesBrands(const uint8_t aData[4], nsACString& aSniffedType) {
+  for (const auto& currentEntry : sFtypEntries) {
+    bool matched = true;
+    MOZ_ASSERT(currentEntry.mLength <= 4,
+               "Pattern is too large to match brand strings.");
+    for (uint32_t j = 0; j < currentEntry.mLength; ++j) {
+      if ((currentEntry.mMask[j] & aData[j]) != currentEntry.mPattern[j]) {
+        matched = false;
+        break;
+      }
+    }
+    if (matched) {
+      // If we eventually remove the "iso" pattern entry per bug 1725190,
+      // this block should be removed and the bug1725190.cr3 test in
+      // test_mediasniffer_ext.js will need to be updated
+      if (!mozilla::StaticPrefs::media_mp4_sniff_iso_brand() &&
+          currentEntry.mLabel == PatternLabel::ftyp_iso) {
+        continue;
+      }
+
+      aSniffedType.AssignASCII(currentEntry.mContentType);
+      AccumulateCategorical(currentEntry.mLabel);
+      return true;
+    }
+  }
+
+  return false;
+}
+
+// This function implements sniffing algorithm for MP4 family file types,
+// including MP4 (described at
+// http://mimesniff.spec.whatwg.org/#signature-for-mp4), M4A (Apple iTunes
+// audio), and 3GPP.
+bool MatchesMP4(const uint8_t* aData, const uint32_t aLength,
+                nsACString& aSniffedType) {
+  if (aLength <= MP4_MIN_BYTES_COUNT) {
+    return false;
+  }
+  // Conversion from big endian to host byte order.
+  uint32_t boxSize =
+      (uint32_t)(aData[3] | aData[2] << 8 | aData[1] << 16 | aData[0] << 24);
+
+  // Boxsize should be evenly divisible by 4.
+  if (boxSize % 4 || aLength < boxSize) {
+    return false;
+  }
+  // The string "ftyp".
+  if (aData[4] != 0x66 || aData[5] != 0x74 || aData[6] != 0x79 ||
+      aData[7] != 0x70) {
+    return false;
+  }
+  if (MatchesBrands(&aData[8], aSniffedType)) {
+    return true;
+  }
+  // Skip minor_version (bytes 12-15).
+  uint32_t bytesRead = 16;
+  while (bytesRead < boxSize) {
+    if (MatchesBrands(&aData[bytesRead], aSniffedType)) {
+      return true;
+    }
+    bytesRead += 4;
+  }
+
+  return false;
+}
+
+static bool MatchesWebM(const uint8_t* aData, const uint32_t aLength) {
+  return nestegg_sniff((uint8_t*)aData, aLength);
+}
+
+// This function implements mp3 sniffing based on parsing
+// packet headers and looking for expected boundaries.
+static bool MatchesMP3(const uint8_t* aData, const uint32_t aLength) {
+  return mp3_sniff(aData, (long)aLength);
+}
+
+static bool MatchesADTS(const uint8_t* aData, const uint32_t aLength) {
+  return mozilla::ADTSDemuxer::ADTSSniffer(aData, aLength);
+}
+
+NS_IMETHODIMP
+nsMediaSniffer::GetMIMETypeFromContent(nsIRequest* aRequest,
+                                       const uint8_t* aData,
+                                       const uint32_t aLength,
+                                       nsACString& aSniffedType) {
+  const uint32_t clampedLength = std::min(aLength, MAX_BYTES_SNIFFED);
+
+  auto maybeUpdate = mozilla::MakeScopeExit([request = RefPtr{aRequest}]() {
+    nsCOMPtr<nsIChannel> channel = do_QueryInterface(request);
+    if (channel && XRE_IsParentProcess()) {
+      if (RefPtr<mozilla::net::nsHttpChannel> httpChannel =
+              do_QueryObject(channel)) {
+        // If the audio or video type pattern matching algorithm given bytes
+        // does not return undefined, then disable the further check and allow
+        // the response.
+        httpChannel->DisableIsOpaqueResponseAllowedAfterSniffCheck(
+            mozilla::net::nsHttpChannel::SnifferType::Media);
+      }
+    };
+  });
+
+  for (const auto& currentEntry : sSnifferEntries) {
+    if (clampedLength < currentEntry.mLength || currentEntry.mLength == 0) {
+      continue;
+    }
+    bool matched = true;
+    for (uint32_t j = 0; j < currentEntry.mLength; ++j) {
+      if ((currentEntry.mMask[j] & aData[j]) != currentEntry.mPattern[j]) {
+        matched = false;
+        break;
+      }
+    }
+    if (matched) {
+      aSniffedType.AssignASCII(currentEntry.mContentType);
+      return NS_OK;
+    }
+  }
+
+  if (MatchesMP4(aData, clampedLength, aSniffedType)) {
+    return NS_OK;
+  }
+
+  if (MatchesWebM(aData, clampedLength)) {
+    aSniffedType.AssignLiteral(VIDEO_WEBM);
+    return NS_OK;
+  }
+
+  // Bug 950023: 512 bytes are often not enough to sniff for mp3.
+  if (MatchesMP3(aData, std::min(aLength, MAX_BYTES_SNIFFED_MP3))) {
+    aSniffedType.AssignLiteral(AUDIO_MP3);
+    return NS_OK;
+  }
+
+  if (MatchesADTS(aData, std::min(aLength, MAX_BYTES_SNIFFED_ADTS))) {
+    aSniffedType.AssignLiteral(AUDIO_AAC);
+    return NS_OK;
+  }
+
+  maybeUpdate.release();
+
+  // Could not sniff the media type, we are required to set it to
+  // application/octet-stream.
+  aSniffedType.AssignLiteral(APPLICATION_OCTET_STREAM);
+  return NS_ERROR_NOT_AVAILABLE;
+}
diff --git a/toolkit/components/mediasniffer/nsMediaSniffer.h b/toolkit/components/mediasniffer/nsMediaSniffer.h
new file mode 100644
index 0000000000..9608e2e643
--- /dev/null
+++ b/toolkit/components/mediasniffer/nsMediaSniffer.h
@@ -0,0 +1,50 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 tw=80 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsMediaSniffer_h
+#define nsMediaSniffer_h
+
+#include "nsIContentSniffer.h"
+#include "mozilla/Attributes.h"
+
+// ed905ba3-c656-480e-934e-6bc35bd36aff
+#define NS_MEDIA_SNIFFER_CID                         \
+  {                                                  \
+    0x3fdd6c28, 0x5b87, 0x4e3e, {                    \
+      0x8b, 0x57, 0x8e, 0x83, 0xc2, 0x3c, 0x1a, 0x6d \
+    }                                                \
+  }
+
+#define NS_MEDIA_SNIFFER_CONTRACTID "@mozilla.org/media/sniffer;1"
+
+#define PATTERN_ENTRY(mask, pattern, contentType)                    \
+  {                                                                  \
+    (const uint8_t*)mask, (const uint8_t*)pattern, sizeof(mask) - 1, \
+        contentType                                                  \
+  }
+
+struct nsMediaSnifferEntry {
+  const uint8_t* mMask;
+  const uint8_t* mPattern;
+  const uint32_t mLength;
+  const char* mContentType;
+};
+
+bool MatchesMP4(const uint8_t* aData, const uint32_t aLength,
+                nsACString& aSniffedType);
+
+class nsMediaSniffer final : public nsIContentSniffer {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSICONTENTSNIFFER
+
+ private:
+  ~nsMediaSniffer() = default;
+
+  static nsMediaSnifferEntry sSnifferEntries[];
+};
+
+#endif
diff --git a/toolkit/components/mediasniffer/test/unit/data/bug1079747.mp4 b/toolkit/components/mediasniffer/test/unit/data/bug1079747.mp4
new file mode 100644
index 0000000000..f00731d7e2
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/bug1079747.mp4
diff --git a/toolkit/components/mediasniffer/test/unit/data/bug1725190.cr3 b/toolkit/components/mediasniffer/test/unit/data/bug1725190.cr3
new file mode 100644
index 0000000000..4e46f36b1d
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/bug1725190.cr3
diff --git a/toolkit/components/mediasniffer/test/unit/data/detodos.mp3 b/toolkit/components/mediasniffer/test/unit/data/detodos.mp3
new file mode 100644
index 0000000000..12e3f89c20
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/detodos.mp3
diff --git a/toolkit/components/mediasniffer/test/unit/data/ff-inst.exe b/toolkit/components/mediasniffer/test/unit/data/ff-inst.exe
new file mode 100644
index 0000000000..0f02f36e1a
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/ff-inst.exe
diff --git a/toolkit/components/mediasniffer/test/unit/data/file.mkv b/toolkit/components/mediasniffer/test/unit/data/file.mkv
new file mode 100644
index 0000000000..4618cda032
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/file.mkv
diff --git a/toolkit/components/mediasniffer/test/unit/data/file.webm b/toolkit/components/mediasniffer/test/unit/data/file.webm
new file mode 100644
index 0000000000..7bc738b8b4
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/file.webm
diff --git a/toolkit/components/mediasniffer/test/unit/data/fl10.mp2 b/toolkit/components/mediasniffer/test/unit/data/fl10.mp2
new file mode 100644
index 0000000000..bf84d73675
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/fl10.mp2
diff --git a/toolkit/components/mediasniffer/test/unit/data/he_free.mp3 b/toolkit/components/mediasniffer/test/unit/data/he_free.mp3
new file mode 100644
index 0000000000..e3da8e6a72
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/he_free.mp3
diff --git a/toolkit/components/mediasniffer/test/unit/data/id3tags.mp3 b/toolkit/components/mediasniffer/test/unit/data/id3tags.mp3
new file mode 100644
index 0000000000..23091e6667
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/id3tags.mp3
diff --git a/toolkit/components/mediasniffer/test/unit/data/mp3-in-riff.wav b/toolkit/components/mediasniffer/test/unit/data/mp3-in-riff.wav
new file mode 100644
index 0000000000..5ccaf351f3
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/mp3-in-riff.wav
diff --git a/toolkit/components/mediasniffer/test/unit/data/notags-bad.mp3 b/toolkit/components/mediasniffer/test/unit/data/notags-bad.mp3
new file mode 100644
index 0000000000..5ad89786fa
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/notags-bad.mp3
diff --git a/toolkit/components/mediasniffer/test/unit/data/notags-scan.mp3 b/toolkit/components/mediasniffer/test/unit/data/notags-scan.mp3
new file mode 100644
index 0000000000..949b7c4687
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/notags-scan.mp3
diff --git a/toolkit/components/mediasniffer/test/unit/data/notags.mp3 b/toolkit/components/mediasniffer/test/unit/data/notags.mp3
new file mode 100644
index 0000000000..c7db943617
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/data/notags.mp3
diff --git a/toolkit/components/mediasniffer/test/unit/test_mediasniffer.js b/toolkit/components/mediasniffer/test/unit/test_mediasniffer.js
new file mode 100644
index 0000000000..b33ec2f590
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/test_mediasniffer.js
@@ -0,0 +1,121 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+const { HttpServer } = ChromeUtils.import("resource://testing-common/httpd.js");
+const { NetUtil } = ChromeUtils.import("resource://gre/modules/NetUtil.jsm");
+
+const PATH = "/file.meh";
+var httpserver = new HttpServer();
+
+// Each time, the data consist in a string that should be sniffed as Ogg.
+const data = "OggS\0meeeh.";
+var testRan = 0;
+
+// If the content-type is not present, or if it's application/octet-stream, it
+// should be sniffed to application/ogg by the media sniffer. Otherwise, it
+// should not be changed.
+const tests = [
+  // Those three first case are the case of a media loaded in a media element.
+  // All three should be sniffed.
+  {
+    contentType: "",
+    expectedContentType: "application/ogg",
+    flags:
+      Ci.nsIChannel.LOAD_CALL_CONTENT_SNIFFERS |
+      Ci.nsIChannel.LOAD_MEDIA_SNIFFER_OVERRIDES_CONTENT_TYPE,
+  },
+  {
+    contentType: "application/octet-stream",
+    expectedContentType: "application/ogg",
+    flags:
+      Ci.nsIChannel.LOAD_CALL_CONTENT_SNIFFERS |
+      Ci.nsIChannel.LOAD_MEDIA_SNIFFER_OVERRIDES_CONTENT_TYPE,
+  },
+  {
+    contentType: "application/something",
+    expectedContentType: "application/ogg",
+    flags:
+      Ci.nsIChannel.LOAD_CALL_CONTENT_SNIFFERS |
+      Ci.nsIChannel.LOAD_MEDIA_SNIFFER_OVERRIDES_CONTENT_TYPE,
+  },
+  // This last cases test the case of a channel opened while allowing content
+  // sniffers to override the content-type, like in the docshell.
+  {
+    contentType: "application/octet-stream",
+    expectedContentType: "application/ogg",
+    flags: Ci.nsIChannel.LOAD_CALL_CONTENT_SNIFFERS,
+  },
+  {
+    contentType: "",
+    expectedContentType: "application/ogg",
+    flags: Ci.nsIChannel.LOAD_CALL_CONTENT_SNIFFERS,
+  },
+  {
+    contentType: "application/something",
+    expectedContentType: "application/ogg",
+    flags: Ci.nsIChannel.LOAD_CALL_CONTENT_SNIFFERS,
+  },
+];
+
+// A basic listener that reads checks the if we sniffed properly.
+var listener = {
+  onStartRequest(request) {
+    Assert.equal(
+      request.QueryInterface(Ci.nsIChannel).contentType,
+      tests[testRan].expectedContentType
+    );
+  },
+
+  onDataAvailable(request, stream, offset, count) {
+    try {
+      var bis = Cc["@mozilla.org/binaryinputstream;1"].createInstance(
+        Ci.nsIBinaryInputStream
+      );
+      bis.setInputStream(stream);
+      bis.readByteArray(bis.available());
+    } catch (ex) {
+      do_throw("Error in onDataAvailable: " + ex);
+    }
+  },
+
+  onStopRequest(request, status) {
+    testRan++;
+    runNext();
+  },
+};
+
+function setupChannel(url, flags) {
+  let uri = "http://localhost:" + httpserver.identity.primaryPort + url;
+  var chan = NetUtil.newChannel({
+    uri,
+    loadUsingSystemPrincipal: true,
+    contentPolicyType: Ci.nsIContentPolicy.TYPE_MEDIA,
+  });
+  chan.loadFlags |= flags;
+  var httpChan = chan.QueryInterface(Ci.nsIHttpChannel);
+  return httpChan;
+}
+
+function runNext() {
+  if (testRan == tests.length) {
+    do_test_finished();
+    return;
+  }
+  var channel = setupChannel(PATH, tests[testRan].flags);
+  httpserver.registerPathHandler(PATH, function (request, response) {
+    response.setHeader("Content-Type", tests[testRan].contentType, false);
+    response.bodyOutputStream.write(data, data.length);
+  });
+  channel.asyncOpen(listener);
+}
+
+function run_test() {
+  httpserver.start(-1);
+  do_test_pending();
+  try {
+    runNext();
+  } catch (e) {
+    print("ERROR - " + e + "\n");
+  }
+}
diff --git a/toolkit/components/mediasniffer/test/unit/test_mediasniffer_ext.js b/toolkit/components/mediasniffer/test/unit/test_mediasniffer_ext.js
new file mode 100644
index 0000000000..5439e5b51d
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/test_mediasniffer_ext.js
@@ -0,0 +1,131 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+var CC = Components.Constructor;
+
+var BinaryOutputStream = CC(
+  "@mozilla.org/binaryoutputstream;1",
+  "nsIBinaryOutputStream",
+  "setOutputStream"
+);
+
+const { HttpServer } = ChromeUtils.import("resource://testing-common/httpd.js");
+const { NetUtil } = ChromeUtils.import("resource://gre/modules/NetUtil.jsm");
+
+var httpserver = new HttpServer();
+
+var testRan = 0;
+
+// The tests files we want to test, and the type we should have after sniffing.
+const tests = [
+  // Real webm and mkv files truncated to 512 bytes.
+  { path: "data/file.webm", expected: "video/webm" },
+  { path: "data/file.mkv", expected: "application/octet-stream" },
+  // MP3 files with and without id3 headers truncated to 512 bytes.
+  // NB these have 208/209 byte frames, but mp3 can require up to
+  // 1445 bytes to detect with our method.
+  { path: "data/id3tags.mp3", expected: "audio/mpeg" },
+  { path: "data/notags.mp3", expected: "audio/mpeg" },
+  // MPEG-2 mp3 files.
+  { path: "data/detodos.mp3", expected: "audio/mpeg" },
+  // Padding bit flipped in the first header: sniffing should fail.
+  { path: "data/notags-bad.mp3", expected: "application/octet-stream" },
+  // Garbage before header: sniffing should fail.
+  { path: "data/notags-scan.mp3", expected: "application/octet-stream" },
+  // VBR from the layer III test patterns. We can't sniff this.
+  { path: "data/he_free.mp3", expected: "application/octet-stream" },
+  // Make sure we reject mp2, which has a similar header.
+  { path: "data/fl10.mp2", expected: "application/octet-stream" },
+  // Truncated ff installer regression test for bug 875769.
+  { path: "data/ff-inst.exe", expected: "application/octet-stream" },
+  // MP4 with invalid box size (0) for "ftyp".
+  { path: "data/bug1079747.mp4", expected: "application/octet-stream" },
+  // An MP3 bytestream in a RIFF container, truncated to 512 bytes.
+  { path: "data/mp3-in-riff.wav", expected: "audio/mpeg" },
+  // The sniffing-relevant portion of a Canon raw image
+  { path: "data/bug1725190.cr3", expected: "application/octet-stream" },
+];
+
+// A basic listener that reads checks the if we sniffed properly.
+var listener = {
+  onStartRequest(request) {
+    info("Sniffing " + tests[testRan].path);
+    Assert.equal(
+      request.QueryInterface(Ci.nsIChannel).contentType,
+      tests[testRan].expected
+    );
+  },
+
+  onDataAvailable(request, stream, offset, count) {
+    try {
+      var bis = Cc["@mozilla.org/binaryinputstream;1"].createInstance(
+        Ci.nsIBinaryInputStream
+      );
+      bis.setInputStream(stream);
+      bis.readByteArray(bis.available());
+    } catch (ex) {
+      do_throw("Error in onDataAvailable: " + ex);
+    }
+  },
+
+  onStopRequest(request, status) {
+    testRan++;
+    runNext();
+  },
+};
+
+function setupChannel(url) {
+  var chan = NetUtil.newChannel({
+    uri: "http://localhost:" + httpserver.identity.primaryPort + url,
+    loadUsingSystemPrincipal: true,
+    contentPolicyType: Ci.nsIContentPolicy.TYPE_MEDIA,
+  });
+  var httpChan = chan.QueryInterface(Ci.nsIHttpChannel);
+  return httpChan;
+}
+
+function runNext() {
+  if (testRan == tests.length) {
+    do_test_finished();
+    return;
+  }
+  var channel = setupChannel("/");
+  channel.asyncOpen(listener);
+}
+
+function getFileContents(aFile) {
+  var fileStream = Cc[
+    "@mozilla.org/network/file-input-stream;1"
+  ].createInstance(Ci.nsIFileInputStream);
+  fileStream.init(aFile, 1, -1, null);
+  var bis = Cc["@mozilla.org/binaryinputstream;1"].createInstance(
+    Ci.nsIBinaryInputStream
+  );
+  bis.setInputStream(fileStream);
+
+  var data = bis.readByteArray(bis.available());
+
+  return data;
+}
+
+function handler(metadata, response) {
+  response.setStatusLine(metadata.httpVersion, 200, "OK");
+  // Send an empty Content-Type, so we are guaranteed to sniff.
+  response.setHeader("Content-Type", "", false);
+  var body = getFileContents(do_get_file(tests[testRan].path));
+  var bos = new BinaryOutputStream(response.bodyOutputStream);
+  bos.writeByteArray(body);
+}
+
+function run_test() {
+  // We use a custom handler so we can change the header to force sniffing.
+  httpserver.registerPathHandler("/", handler);
+  httpserver.start(-1);
+  do_test_pending();
+  try {
+    runNext();
+  } catch (e) {
+    print("ERROR - " + e + "\n");
+  }
+}
diff --git a/toolkit/components/mediasniffer/test/unit/xpcshell.ini b/toolkit/components/mediasniffer/test/unit/xpcshell.ini
new file mode 100644
index 0000000000..9b3464a1b3
--- /dev/null
+++ b/toolkit/components/mediasniffer/test/unit/xpcshell.ini
@@ -0,0 +1,20 @@
+[DEFAULT]
+head =
+skip-if = toolkit == 'android'
+support-files =
+  data/bug1079747.mp4
+  data/bug1725190.cr3
+  data/detodos.mp3
+  data/ff-inst.exe
+  data/file.mkv
+  data/file.webm
+  data/fl10.mp2
+  data/he_free.mp3
+  data/id3tags.mp3
+  data/mp3-in-riff.wav
+  data/notags-bad.mp3
+  data/notags-scan.mp3
+  data/notags.mp3
+
+[test_mediasniffer.js]
+[test_mediasniffer_ext.js]