/*
* Copyright 2022 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.media3.extractor.avi;
import androidx.annotation.Nullable;
import androidx.media3.common.C;
import androidx.media3.common.Format;
import androidx.media3.common.MimeTypes;
import androidx.media3.common.util.Log;
import androidx.media3.common.util.ParsableByteArray;
import androidx.media3.common.util.Util;
import com.google.common.collect.ImmutableList;
/** Holds the {@link Format} information contained in an STRF chunk. */
/* package */ final class StreamFormatChunk implements AviChunk {
private static final String TAG = "StreamFormatChunk";
@Nullable
public static AviChunk parseFrom(int trackType, ParsableByteArray body) {
if (trackType == C.TRACK_TYPE_VIDEO) {
return parseBitmapInfoHeader(body);
} else if (trackType == C.TRACK_TYPE_AUDIO) {
return parseWaveFormatEx(body);
} else {
Log.w(
TAG,
"Ignoring strf box for unsupported track type: " + Util.getTrackTypeString(trackType));
return null;
}
}
public final Format format;
public StreamFormatChunk(Format format) {
this.format = format;
}
@Override
public int getType() {
return AviExtractor.FOURCC_strf;
}
@Nullable
private static AviChunk parseBitmapInfoHeader(ParsableByteArray body) {
body.skipBytes(4); // biSize.
int width = body.readLittleEndianInt();
int height = body.readLittleEndianInt();
body.skipBytes(4); // biPlanes (2 bytes), biBitCount (2 bytes).
int compression = body.readLittleEndianInt();
String mimeType = getMimeTypeFromCompression(compression);
if (mimeType == null) {
Log.w(TAG, "Ignoring track with unsupported compression " + compression);
return null;
}
Format.Builder formatBuilder = new Format.Builder();
formatBuilder.setWidth(width).setHeight(height).setSampleMimeType(mimeType);
return new StreamFormatChunk(formatBuilder.build());
}
// Syntax defined by the WAVEFORMATEX structure. See
// https://docs.microsoft.com/en-us/previous-versions/dd757713(v=vs.85).
@Nullable
private static AviChunk parseWaveFormatEx(ParsableByteArray body) {
int formatTag = body.readLittleEndianUnsignedShort();
@Nullable String mimeType = getMimeTypeFromTag(formatTag);
if (mimeType == null) {
Log.w(TAG, "Ignoring track with unsupported format tag " + formatTag);
return null;
}
int channelCount = body.readLittleEndianUnsignedShort();
int samplesPerSecond = body.readLittleEndianInt();
body.skipBytes(6); // averageBytesPerSecond (4 bytes), nBlockAlign (2 bytes).
int bitsPerSample = body.readUnsignedShort();
int pcmEncoding = Util.getPcmEncoding(bitsPerSample);
int cbSize = body.readLittleEndianUnsignedShort();
byte[] codecData = new byte[cbSize];
body.readBytes(codecData, /* offset= */ 0, codecData.length);
Format.Builder formatBuilder = new Format.Builder();
formatBuilder
.setSampleMimeType(mimeType)
.setChannelCount(channelCount)
.setSampleRate(samplesPerSecond);
if (MimeTypes.AUDIO_RAW.equals(mimeType) && pcmEncoding != C.ENCODING_INVALID) {
formatBuilder.setPcmEncoding(pcmEncoding);
}
if (MimeTypes.AUDIO_AAC.equals(mimeType) && codecData.length > 0) {
formatBuilder.setInitializationData(ImmutableList.of(codecData));
}
return new StreamFormatChunk(formatBuilder.build());
}
@Nullable
private static String getMimeTypeFromTag(int tag) {
switch (tag) {
case 0x1: // WAVE_FORMAT_PCM
return MimeTypes.AUDIO_RAW;
case 0x55: // WAVE_FORMAT_MPEGLAYER3
return MimeTypes.AUDIO_MPEG;
case 0xff: // WAVE_FORMAT_AAC
return MimeTypes.AUDIO_AAC;
case 0x2000: // WAVE_FORMAT_DVM - AC3
return MimeTypes.AUDIO_AC3;
case 0x2001: // WAVE_FORMAT_DTS2
return MimeTypes.AUDIO_DTS;
default:
return null;
}
}
@Nullable
private static String getMimeTypeFromCompression(int compression) {
switch (compression) {
case 0x3234504d: // MP42
return MimeTypes.VIDEO_MP42;
case 0x3334504d: // MP43
return MimeTypes.VIDEO_MP43;
case 0x34363248: // H264
case 0x31637661: // avc1
case 0x31435641: // AVC1
return MimeTypes.VIDEO_H264;
case 0x44495633: // 3VID
case 0x78766964: // divx
case 0x58564944: // DIVX
case 0x30355844: // DX50
case 0x34504d46: // FMP4
case 0x64697678: // xvid
case 0x44495658: // XVID
return MimeTypes.VIDEO_MP4V;
case 0x47504a4d: // MJPG
case 0x67706a6d: // mjpg
return MimeTypes.VIDEO_MJPEG;
default:
return null;
}
}
}