diff options
Diffstat (limited to 'mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/SampleDataQueue.java')
| -rw-r--r-- | mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/SampleDataQueue.java | 472 |
1 files changed, 472 insertions, 0 deletions
diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/SampleDataQueue.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/SampleDataQueue.java new file mode 100644 index 0000000000..81933a468d --- /dev/null +++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/source/SampleDataQueue.java @@ -0,0 +1,472 @@ +/* + * Copyright (C) 2019 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 org.mozilla.thirdparty.com.google.android.exoplayer2.source; + +import androidx.annotation.Nullable; +import org.mozilla.thirdparty.com.google.android.exoplayer2.C; +import org.mozilla.thirdparty.com.google.android.exoplayer2.decoder.CryptoInfo; +import org.mozilla.thirdparty.com.google.android.exoplayer2.decoder.DecoderInputBuffer; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.ExtractorInput; +import org.mozilla.thirdparty.com.google.android.exoplayer2.extractor.TrackOutput.CryptoData; +import org.mozilla.thirdparty.com.google.android.exoplayer2.source.SampleQueue.SampleExtrasHolder; +import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.Allocation; +import org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.Allocator; +import org.mozilla.thirdparty.com.google.android.exoplayer2.util.ParsableByteArray; +import java.io.EOFException; +import java.io.IOException; +import java.nio.ByteBuffer; +import java.util.Arrays; + +/** A queue of media sample data. */ +/* package */ class SampleDataQueue { + + private static final int INITIAL_SCRATCH_SIZE = 32; + + private final Allocator allocator; + private final int allocationLength; + private final ParsableByteArray scratch; + + // References into the linked list of allocations. + private AllocationNode firstAllocationNode; + private AllocationNode readAllocationNode; + private AllocationNode writeAllocationNode; + + // Accessed only by the loading thread (or the consuming thread when there is no loading thread). + private long totalBytesWritten; + + public SampleDataQueue(Allocator allocator) { + this.allocator = allocator; + allocationLength = allocator.getIndividualAllocationLength(); + scratch = new ParsableByteArray(INITIAL_SCRATCH_SIZE); + firstAllocationNode = new AllocationNode(/* startPosition= */ 0, allocationLength); + readAllocationNode = firstAllocationNode; + writeAllocationNode = firstAllocationNode; + } + + // Called by the consuming thread, but only when there is no loading thread. + + /** Clears all sample data. */ + public void reset() { + clearAllocationNodes(firstAllocationNode); + firstAllocationNode = new AllocationNode(0, allocationLength); + readAllocationNode = firstAllocationNode; + writeAllocationNode = firstAllocationNode; + totalBytesWritten = 0; + allocator.trim(); + } + + /** + * Discards sample data bytes from the write side of the queue. + * + * @param totalBytesWritten The reduced total number of bytes written after the samples have been + * discarded, or 0 if the queue is now empty. + */ + public void discardUpstreamSampleBytes(long totalBytesWritten) { + this.totalBytesWritten = totalBytesWritten; + if (this.totalBytesWritten == 0 + || this.totalBytesWritten == firstAllocationNode.startPosition) { + clearAllocationNodes(firstAllocationNode); + firstAllocationNode = new AllocationNode(this.totalBytesWritten, allocationLength); + readAllocationNode = firstAllocationNode; + writeAllocationNode = firstAllocationNode; + } else { + // Find the last node containing at least 1 byte of data that we need to keep. + AllocationNode lastNodeToKeep = firstAllocationNode; + while (this.totalBytesWritten > lastNodeToKeep.endPosition) { + lastNodeToKeep = lastNodeToKeep.next; + } + // Discard all subsequent nodes. + AllocationNode firstNodeToDiscard = lastNodeToKeep.next; + clearAllocationNodes(firstNodeToDiscard); + // Reset the successor of the last node to be an uninitialized node. + lastNodeToKeep.next = new AllocationNode(lastNodeToKeep.endPosition, allocationLength); + // Update writeAllocationNode and readAllocationNode as necessary. + writeAllocationNode = + this.totalBytesWritten == lastNodeToKeep.endPosition + ? lastNodeToKeep.next + : lastNodeToKeep; + if (readAllocationNode == firstNodeToDiscard) { + readAllocationNode = lastNodeToKeep.next; + } + } + } + + // Called by the consuming thread. + + /** Rewinds the read position to the first sample in the queue. */ + public void rewind() { + readAllocationNode = firstAllocationNode; + } + + /** + * Reads data from the rolling buffer to populate a decoder input buffer. + * + * @param buffer The buffer to populate. + * @param extrasHolder The extras holder whose offset should be read and subsequently adjusted. + */ + public void readToBuffer(DecoderInputBuffer buffer, SampleExtrasHolder extrasHolder) { + // Read encryption data if the sample is encrypted. + if (buffer.isEncrypted()) { + readEncryptionData(buffer, extrasHolder); + } + // Read sample data, extracting supplemental data into a separate buffer if needed. + if (buffer.hasSupplementalData()) { + // If there is supplemental data, the sample data is prefixed by its size. + scratch.reset(4); + readData(extrasHolder.offset, scratch.data, 4); + int sampleSize = scratch.readUnsignedIntToInt(); + extrasHolder.offset += 4; + extrasHolder.size -= 4; + + // Write the sample data. + buffer.ensureSpaceForWrite(sampleSize); + readData(extrasHolder.offset, buffer.data, sampleSize); + extrasHolder.offset += sampleSize; + extrasHolder.size -= sampleSize; + + // Write the remaining data as supplemental data. + buffer.resetSupplementalData(extrasHolder.size); + readData(extrasHolder.offset, buffer.supplementalData, extrasHolder.size); + } else { + // Write the sample data. + buffer.ensureSpaceForWrite(extrasHolder.size); + readData(extrasHolder.offset, buffer.data, extrasHolder.size); + } + } + + /** + * Advances the read position to the specified absolute position. + * + * @param absolutePosition The new absolute read position. May be {@link C#POSITION_UNSET}, in + * which case calling this method is a no-op. + */ + public void discardDownstreamTo(long absolutePosition) { + if (absolutePosition == C.POSITION_UNSET) { + return; + } + while (absolutePosition >= firstAllocationNode.endPosition) { + // Advance firstAllocationNode to the specified absolute position. Also clear nodes that are + // advanced past, and return their underlying allocations to the allocator. + allocator.release(firstAllocationNode.allocation); + firstAllocationNode = firstAllocationNode.clear(); + } + if (readAllocationNode.startPosition < firstAllocationNode.startPosition) { + // We discarded the node referenced by readAllocationNode. We need to advance it to the first + // remaining node. + readAllocationNode = firstAllocationNode; + } + } + + // Called by the loading thread. + + public long getTotalBytesWritten() { + return totalBytesWritten; + } + + public int sampleData(ExtractorInput input, int length, boolean allowEndOfInput) + throws IOException, InterruptedException { + length = preAppend(length); + int bytesAppended = + input.read( + writeAllocationNode.allocation.data, + writeAllocationNode.translateOffset(totalBytesWritten), + length); + if (bytesAppended == C.RESULT_END_OF_INPUT) { + if (allowEndOfInput) { + return C.RESULT_END_OF_INPUT; + } + throw new EOFException(); + } + postAppend(bytesAppended); + return bytesAppended; + } + + public void sampleData(ParsableByteArray buffer, int length) { + while (length > 0) { + int bytesAppended = preAppend(length); + buffer.readBytes( + writeAllocationNode.allocation.data, + writeAllocationNode.translateOffset(totalBytesWritten), + bytesAppended); + length -= bytesAppended; + postAppend(bytesAppended); + } + } + + // Private methods. + + /** + * Reads encryption data for the current sample. + * + * <p>The encryption data is written into {@link DecoderInputBuffer#cryptoInfo}, and {@link + * SampleExtrasHolder#size} is adjusted to subtract the number of bytes that were read. The same + * value is added to {@link SampleExtrasHolder#offset}. + * + * @param buffer The buffer into which the encryption data should be written. + * @param extrasHolder The extras holder whose offset should be read and subsequently adjusted. + */ + private void readEncryptionData(DecoderInputBuffer buffer, SampleExtrasHolder extrasHolder) { + long offset = extrasHolder.offset; + + // Read the signal byte. + scratch.reset(1); + readData(offset, scratch.data, 1); + offset++; + byte signalByte = scratch.data[0]; + boolean subsampleEncryption = (signalByte & 0x80) != 0; + int ivSize = signalByte & 0x7F; + + // Read the initialization vector. + CryptoInfo cryptoInfo = buffer.cryptoInfo; + if (cryptoInfo.iv == null) { + cryptoInfo.iv = new byte[16]; + } else { + // Zero out cryptoInfo.iv so that if ivSize < 16, the remaining bytes are correctly set to 0. + Arrays.fill(cryptoInfo.iv, (byte) 0); + } + readData(offset, cryptoInfo.iv, ivSize); + offset += ivSize; + + // Read the subsample count, if present. + int subsampleCount; + if (subsampleEncryption) { + scratch.reset(2); + readData(offset, scratch.data, 2); + offset += 2; + subsampleCount = scratch.readUnsignedShort(); + } else { + subsampleCount = 1; + } + + // Write the clear and encrypted subsample sizes. + @Nullable int[] clearDataSizes = cryptoInfo.numBytesOfClearData; + if (clearDataSizes == null || clearDataSizes.length < subsampleCount) { + clearDataSizes = new int[subsampleCount]; + } + @Nullable int[] encryptedDataSizes = cryptoInfo.numBytesOfEncryptedData; + if (encryptedDataSizes == null || encryptedDataSizes.length < subsampleCount) { + encryptedDataSizes = new int[subsampleCount]; + } + if (subsampleEncryption) { + int subsampleDataLength = 6 * subsampleCount; + scratch.reset(subsampleDataLength); + readData(offset, scratch.data, subsampleDataLength); + offset += subsampleDataLength; + scratch.setPosition(0); + for (int i = 0; i < subsampleCount; i++) { + clearDataSizes[i] = scratch.readUnsignedShort(); + encryptedDataSizes[i] = scratch.readUnsignedIntToInt(); + } + } else { + clearDataSizes[0] = 0; + encryptedDataSizes[0] = extrasHolder.size - (int) (offset - extrasHolder.offset); + } + + // Populate the cryptoInfo. + CryptoData cryptoData = extrasHolder.cryptoData; + cryptoInfo.set( + subsampleCount, + clearDataSizes, + encryptedDataSizes, + cryptoData.encryptionKey, + cryptoInfo.iv, + cryptoData.cryptoMode, + cryptoData.encryptedBlocks, + cryptoData.clearBlocks); + + // Adjust the offset and size to take into account the bytes read. + int bytesRead = (int) (offset - extrasHolder.offset); + extrasHolder.offset += bytesRead; + extrasHolder.size -= bytesRead; + } + + /** + * Reads data from the front of the rolling buffer. + * + * @param absolutePosition The absolute position from which data should be read. + * @param target The buffer into which data should be written. + * @param length The number of bytes to read. + */ + private void readData(long absolutePosition, ByteBuffer target, int length) { + advanceReadTo(absolutePosition); + int remaining = length; + while (remaining > 0) { + int toCopy = Math.min(remaining, (int) (readAllocationNode.endPosition - absolutePosition)); + Allocation allocation = readAllocationNode.allocation; + target.put(allocation.data, readAllocationNode.translateOffset(absolutePosition), toCopy); + remaining -= toCopy; + absolutePosition += toCopy; + if (absolutePosition == readAllocationNode.endPosition) { + readAllocationNode = readAllocationNode.next; + } + } + } + + /** + * Reads data from the front of the rolling buffer. + * + * @param absolutePosition The absolute position from which data should be read. + * @param target The array into which data should be written. + * @param length The number of bytes to read. + */ + private void readData(long absolutePosition, byte[] target, int length) { + advanceReadTo(absolutePosition); + int remaining = length; + while (remaining > 0) { + int toCopy = Math.min(remaining, (int) (readAllocationNode.endPosition - absolutePosition)); + Allocation allocation = readAllocationNode.allocation; + System.arraycopy( + allocation.data, + readAllocationNode.translateOffset(absolutePosition), + target, + length - remaining, + toCopy); + remaining -= toCopy; + absolutePosition += toCopy; + if (absolutePosition == readAllocationNode.endPosition) { + readAllocationNode = readAllocationNode.next; + } + } + } + + /** + * Advances the read position to the specified absolute position. + * + * @param absolutePosition The position to which {@link #readAllocationNode} should be advanced. + */ + private void advanceReadTo(long absolutePosition) { + while (absolutePosition >= readAllocationNode.endPosition) { + readAllocationNode = readAllocationNode.next; + } + } + + /** + * Clears allocation nodes starting from {@code fromNode}. + * + * @param fromNode The node from which to clear. + */ + private void clearAllocationNodes(AllocationNode fromNode) { + if (!fromNode.wasInitialized) { + return; + } + // Bulk release allocations for performance (it's significantly faster when using + // DefaultAllocator because the allocator's lock only needs to be acquired and released once) + // [Internal: See b/29542039]. + int allocationCount = + (writeAllocationNode.wasInitialized ? 1 : 0) + + ((int) (writeAllocationNode.startPosition - fromNode.startPosition) + / allocationLength); + Allocation[] allocationsToRelease = new Allocation[allocationCount]; + AllocationNode currentNode = fromNode; + for (int i = 0; i < allocationsToRelease.length; i++) { + allocationsToRelease[i] = currentNode.allocation; + currentNode = currentNode.clear(); + } + allocator.release(allocationsToRelease); + } + + /** + * Called before writing sample data to {@link #writeAllocationNode}. May cause {@link + * #writeAllocationNode} to be initialized. + * + * @param length The number of bytes that the caller wishes to write. + * @return The number of bytes that the caller is permitted to write, which may be less than + * {@code length}. + */ + private int preAppend(int length) { + if (!writeAllocationNode.wasInitialized) { + writeAllocationNode.initialize( + allocator.allocate(), + new AllocationNode(writeAllocationNode.endPosition, allocationLength)); + } + return Math.min(length, (int) (writeAllocationNode.endPosition - totalBytesWritten)); + } + + /** + * Called after writing sample data. May cause {@link #writeAllocationNode} to be advanced. + * + * @param length The number of bytes that were written. + */ + private void postAppend(int length) { + totalBytesWritten += length; + if (totalBytesWritten == writeAllocationNode.endPosition) { + writeAllocationNode = writeAllocationNode.next; + } + } + + /** A node in a linked list of {@link Allocation}s held by the output. */ + private static final class AllocationNode { + + /** The absolute position of the start of the data (inclusive). */ + public final long startPosition; + /** The absolute position of the end of the data (exclusive). */ + public final long endPosition; + /** Whether the node has been initialized. Remains true after {@link #clear()}. */ + public boolean wasInitialized; + /** The {@link Allocation}, or {@code null} if the node is not initialized. */ + @Nullable public Allocation allocation; + /** + * The next {@link AllocationNode} in the list, or {@code null} if the node has not been + * initialized. Remains set after {@link #clear()}. + */ + @Nullable public AllocationNode next; + + /** + * @param startPosition See {@link #startPosition}. + * @param allocationLength The length of the {@link Allocation} with which this node will be + * initialized. + */ + public AllocationNode(long startPosition, int allocationLength) { + this.startPosition = startPosition; + this.endPosition = startPosition + allocationLength; + } + + /** + * Initializes the node. + * + * @param allocation The node's {@link Allocation}. + * @param next The next {@link AllocationNode}. + */ + public void initialize(Allocation allocation, AllocationNode next) { + this.allocation = allocation; + this.next = next; + wasInitialized = true; + } + + /** + * Gets the offset into the {@link #allocation}'s {@link Allocation#data} that corresponds to + * the specified absolute position. + * + * @param absolutePosition The absolute position. + * @return The corresponding offset into the allocation's data. + */ + public int translateOffset(long absolutePosition) { + return (int) (absolutePosition - startPosition) + allocation.offset; + } + + /** + * Clears {@link #allocation} and {@link #next}. + * + * @return The cleared next {@link AllocationNode}. + */ + public AllocationNode clear() { + allocation = null; + AllocationNode temp = next; + next = null; + return temp; + } + } +} |