Adding ChunkDemuxer implementation.

media/filters/webm_parser.h

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+#ifndef MEDIA_FILTERS_WEBM_PARSER_H_

[scherkus (not reviewing), 2011/06/22 17:31:09]

nit: add space before

+#define MEDIA_FILTERS_WEBM_PARSER_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+
+namespace media {

[scherkus (not reviewing), 2011/06/22 17:31:09]

I don't see any reason why this needs to be inside media/filters as opposed to
media/base

if we're really interested it might be worth having media/webm folder

[acolwell GONE FROM CHROMIUM, 2011/06/23 16:51:28]

Done. Moved to webm folder.

+
+const int kWebMIdAspectRatioType = 0x54B3;

[scherkus (not reviewing), 2011/06/22 17:31:09]

typically initialize these in .cc

would it make sense to move these to a webm_constants.h file?

[acolwell GONE FROM CHROMIUM, 2011/06/23 16:51:28]

Done. Moved to webm_constants.h

+const int kWebMIdAudio = 0xE1;
+const int kWebMIdBitDepth = 0x6264;
+const int kWebMIdBlock = 0xA1;
+const int kWebMIdBlockGroup = 0xA0;
+const int kWebMIdChannels = 0x9F;
+const int kWebMIdCluster = 0x1f43b675;
+const int kWebMIdCodecID = 0x86;
+const int kWebMIdCodecName = 0x258688;
+const int kWebMIdCodecPrivate = 0x63A2;
+const int kWebMIdDateUTC = 0x4461;
+const int kWebMIdDefaultDuration = 0x23E383;
+const int kWebMIdDisplayHeight = 0x54BA;
+const int kWebMIdDisplayUnit = 0x54B2;
+const int kWebMIdDisplayWidth = 0x54B0;
+const int kWebMIdDuration = 0x4489;
+const int kWebMIdFlagDefault = 0x88;
+const int kWebMIdFlagEnabled = 0xB9;
+const int kWebMIdFlagForced = 0x55AA;
+const int kWebMIdFlagInterlaced = 0x9A;
+const int kWebMIdFlagLacing = 0x9C;
+const int kWebMIdInfo = 0x1549A966;
+const int kWebMIdLanguage = 0x22B59C;
+const int kWebMIdMuxingApp = 0x4D80;
+const int kWebMIdName = 0x536E;
+const int kWebMIdOutputSamplingFrequency = 0x78B5;
+const int kWebMIdPixelCropBottom = 0x54AA;
+const int kWebMIdPixelCropLeft = 0x54CC;
+const int kWebMIdPixelCropRight = 0x54DD;
+const int kWebMIdPixelCropTop = 0x54BB;
+const int kWebMIdPixelHeight = 0xBA;
+const int kWebMIdPixelWidth = 0xB0;
+const int kWebMIdSamplingFrequency = 0xB5;
+const int kWebMIdSegmentUID = 0x73A4;
+const int kWebMIdSimpleBlock = 0xA3;
+const int kWebMIdStereoMode = 0x53B8;
+const int kWebMIdTimecode = 0xE7;
+const int kWebMIdTimecodeScale = 0x2AD7B1;
+const int kWebMIdTitle = 0x7BA9;
+const int kWebMIdTrackEntry = 0xAE;
+const int kWebMIdTrackNumber = 0xD7;
+const int kWebMIdTrackType = 0x83;
+const int kWebMIdTrackUID = 0x73C5;
+const int kWebMIdTracks = 0x1654AE6B;
+const int kWebMIdVideo = 0xE0;
+const int kWebMIdWritingApp = 0x5741;
+
+// Interface for receiving WebM parser events.
+//
+// Each method is called when an element of the specified type is parsed.
+// The ID of the element that was parsed is given along with the value
+// stored in the element. List elements generate calls at the start and
+// end of the list. Any pointers passed to these methods are only guarenteed

[scherkus (not reviewing), 2011/06/22 17:31:09]

guaranteed

[acolwell GONE FROM CHROMIUM, 2011/06/23 16:51:28]

Done.

+// to be valid for the life of that call. Once the call returns the pointer
+// may become invalid. Each method returns a bool that indicates whether the

[scherkus (not reviewing), 2011/06/22 17:31:09]

nit: previous sentence says pointers are only guaranteed to be valid, but
following sentence says "may" become invalid!

when in doubt, trim down the comment to absolutes

[acolwell GONE FROM CHROMIUM, 2011/06/23 16:51:28]

Done.

+// parsed data is valid. If false is returned then the parse is immediately
+// terminated and an error is reported by the parser.
+class WebMParserClient {
+ public:
+  virtual ~WebMParserClient();
+
+  virtual bool OnListStart(int id) = 0;
+  virtual bool OnListEnd(int id) = 0;
+  virtual bool OnUInt(int id, int64 val) = 0;
+  virtual bool OnFloat(int id, double val) = 0;
+  virtual bool OnBinary(int id, const uint8* data, int size) = 0;
+  virtual bool OnString(int id, const std::string& str) = 0;
+  virtual bool OnSimpleBlock(int track_num, int timecode,
+                             int flags,
+                             const uint8* data, int size) = 0;
+};
+
+// Parses a buffer that contains INFO & TRACKS elements.
+int webm_parse_headers(WebMParserClient* client,

[scherkus (not reviewing), 2011/06/22 17:31:09]

this looks like a non-trivial method -- Perhaps ParseWebMHeaders

ParseWebMCluster

?

[acolwell GONE FROM CHROMIUM, 2011/06/23 16:51:28]

Done.

+                       const uint8* buf, int size);
+
+// Parses a buffer that contains a CLUSTER element.
+int webm_parse_cluster(WebMParserClient* client,

[scherkus (not reviewing), 2011/06/22 17:31:09]

docs for these methods?

I notice they return -1 -- what does that mean?

I also noticed a ton of -1s... why not true/false?

[acolwell GONE FROM CHROMIUM, 2011/06/23 16:51:28]

I've added comments to explain the return value. These methods return the number
of bytes parsed on success and -1 on parse failure.

+                       const uint8* buf, int size);
+}  // namespace media
+
+#endif  // MEDIA_FILTERS_WEBM_PARSER_H_