Implement ISO BMFF support in Media Source.

media/mp4/avc.cc

+// Copyright (c) 2012 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.
+
+#include "media/mp4/avc.h"
+
+#include "media/mp4/box_reader.h"
+#include <algorithm>

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

nit: system header files come right after avc.h 

[strobe_, 2012/06/07 16:33:54]

Done.

+
+namespace media {
+namespace mp4 {
+
+const static uint8 kAnnexBStartCode[] = {0, 0, 0, 1};
+const static size_t kAnnexBStartCodeSize = 4;

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

nit: use int

[strobe_, 2012/06/07 22:04:22]

Done.

+
+AVCDecoderConfigurationRecord::AVCDecoderConfigurationRecord() {};
+AVCDecoderConfigurationRecord::~AVCDecoderConfigurationRecord() {};
+
+bool Parse(BoxReader* r, AVCDecoderConfigurationRecord* avcc) {

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

nit: rename r -> reader & avcc to something more descriptive like avc_config

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

Forward declared in avc.h like the other methods.

[strobe_, 2012/06/07 16:33:54]

Done.

[strobe_, 2012/06/07 16:33:54]

Doing this creates an include loop with box_definitions.h (where it's currently
declared). This problem will go away in the forthcoming patch to make Parse() a
virtual method.

+
+  RCHECK(r->Read(&avcc->version) && avcc->version == 1 &&

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

Change read signatures to include size. ie Read1Byte(), Read4Bytes()

[strobe_, 2012/06/07 16:33:54]

In progress.

+         r->Read(&avcc->profile_indication) &&
+         r->Read(&avcc->profile_compatibility) &&
+         r->Read(&avcc->avc_level));
+
+  uint8 length_size_minus_one;

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

nit: use int

+  RCHECK(r->Read(&length_size_minus_one) &&
+         (length_size_minus_one & 0xfc) == 0xfc);
+  avcc->length_size = (length_size_minus_one & 0x3) + 1;
+
+  uint8 num_sps;

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

nit: use int

+  RCHECK(r->Read(&num_sps) && (num_sps & 0xe0) == 0xe0);
+  num_sps &= 0x1f;
+
+  avcc->spses.resize(num_sps);
+  for (int i = 0; i < num_sps; i++) {
+    uint16 sps_length;

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

nit: use int

+    RCHECK(r->Read(&sps_length) &&
+           r->Read(&avcc->spses[i], sps_length));
+  }
+
+  uint8 num_pps;

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

nit:use int here and various places below.

+  RCHECK(r->Read(&num_pps));
+
+  avcc->ppses.resize(num_pps);
+  for (int i = 0; i < num_pps; i++) {
+    uint16 pps_length;
+    RCHECK(r->Read(&pps_length) &&
+           r->Read(&avcc->ppses[i], pps_length));
+  }
+
+  return true;
+}
+
+bool ConvertAVCCToAnnexBInPlaceForLengthSize4(size_t buf_size, uint8* buf) {

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

Add static if only used in this file. Otherwise add forward decl to .h.

[strobe_, 2012/06/07 22:04:22]

Done.

+  const size_t kLengthSize = 4;
+  size_t pos = 0;
+  while (pos + kLengthSize < buf_size) {
+    uint32 nal_size = (((uint32) buf[pos])   << 24)

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

use static_cast<>

[strobe_, 2012/06/07 16:33:54]

Done. (Changed to match style used in BufferReader::Read.)

+                    + (((uint32) buf[pos+1]) << 16)
+                    + (((uint32) buf[pos+2]) << 8)
+                    + buf[pos+3];
+    memcpy(&buf[pos], kAnnexBStartCode, kAnnexBStartCodeSize);
+    pos += kLengthSize + nal_size;
+  }
+  return pos == buf_size;
+}
+
+bool ConvertAVCCToAnnexB(uint8 length_size, std::vector<uint8>* buffer) {

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

use int for length_size

[strobe_, 2012/06/07 16:33:54]

Done.

+  RCHECK(length_size == 1 || length_size == 2 || length_size == 4);
+
+  if (length_size == 4) {
+    return ConvertAVCCToAnnexBInPlaceForLengthSize4(buffer->size(),
+                                                    &((*buffer)[0]));
+  } else {
+    std::vector<uint8_t> temp;
+    temp.swap(*buffer);
+    buffer->reserve(temp.size() + 32);
+
+    size_t pos = 0;
+    while (pos + length_size < temp.size()) {
+      uint32 nal_size = temp[pos];

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

use int

[strobe_, 2012/06/07 16:33:54]

Done.

+      if (length_size == 2) nal_size = (nal_size << 8) + temp[pos+1];
+      pos += length_size;
+
+      RCHECK(pos + nal_size <= temp.size());
+      buffer->insert(buffer->end(), kAnnexBStartCode,
+                     kAnnexBStartCode + kAnnexBStartCodeSize);
+      buffer->insert(buffer->end(), temp.begin() + pos,
+                     temp.begin() + pos + nal_size);
+      pos += nal_size;
+    }
+    return pos == temp.size();
+  }
+}
+
+ChannelLayout ConvertAACChannelCountToChannelLayout(uint16 count) {
+  switch (count) {
+    case 1:
+      return CHANNEL_LAYOUT_MONO;
+    case 2:
+      return CHANNEL_LAYOUT_STEREO;
+    case 3:
+      return CHANNEL_LAYOUT_SURROUND;
+    case 4:
+      return CHANNEL_LAYOUT_4_0;
+    case 5:
+      return CHANNEL_LAYOUT_5_0;
+    case 6:
+      return CHANNEL_LAYOUT_5_1;
+    case 8:
+      return CHANNEL_LAYOUT_7_1;
+    default:
+      return CHANNEL_LAYOUT_UNSUPPORTED;
+  }
+}
+
+}
+}