See av1C configuration record syntax in this spec. + * + *
See av1C OBU syntax in this spec. + * + *
The sections referenced in the method are from these specs. + * + * @param data The av1C atom data. + * @return {@link ColorInfo} parsed from the av1C data. + */ + private static ColorInfo parseAv1c(ParsableByteArray data) { + ColorInfo.Builder colorInfo = new ColorInfo.Builder(); + ParsableBitArray bitArray = new ParsableBitArray(data.getData()); + bitArray.setPosition(data.getPosition() * 8); // Convert byte to bit position. + + // Parse av1C config record for bitdepth info. + // See https://aomediacodec.github.io/av1-isobmff/#av1codecconfigurationbox-syntax. + bitArray.skipBytes(1); // marker, version + int seqProfile = bitArray.readBits(3); // seq_profile + bitArray.skipBits(6); // seq_level_idx_0, seq_tier_0 + boolean highBitdepth = bitArray.readBit(); // high_bitdepth + boolean twelveBit = bitArray.readBit(); // twelve_bit + if (seqProfile == 2 && highBitdepth) { + colorInfo.setLumaBitdepth(twelveBit ? 12 : 10); + colorInfo.setChromaBitdepth(twelveBit ? 12 : 10); + } else if (seqProfile <= 2) { + colorInfo.setLumaBitdepth(highBitdepth ? 10 : 8); + colorInfo.setChromaBitdepth(highBitdepth ? 10 : 8); + } + // Skip monochrome, chroma_subsampling_x, chroma_subsampling_y, chroma_sample_position, + // reserved and initial_presentation_delay. + bitArray.skipBits(13); + + // 5.3.1. General OBU syntax + bitArray.skipBit(); // obu_forbidden_bit + int obuType = bitArray.readBits(4); // obu_type + if (obuType != 1) { // obu_type != OBU_SEQUENCE_HEADER + Log.i(TAG, "Unsupported obu_type: " + obuType); + return colorInfo.build(); + } + if (bitArray.readBit()) { // obu_extension_flag + Log.i(TAG, "Unsupported obu_extension_flag"); + return colorInfo.build(); + } + boolean obuHasSizeField = bitArray.readBit(); // obu_has_size_field + bitArray.skipBit(); // obu_reserved_1bit + // obu_size is unsigned leb128 and if obu_size <= 127 then it can be simplified as readBits(8). + if (obuHasSizeField && bitArray.readBits(8) > 127) { // obu_size + Log.i(TAG, "Excessive obu_size"); + return colorInfo.build(); + } + // 5.5.1. General OBU sequence header syntax + int obuSeqHeaderSeqProfile = bitArray.readBits(3); // seq_profile + bitArray.skipBit(); // still_picture + if (bitArray.readBit()) { // reduced_still_picture_header + Log.i(TAG, "Unsupported reduced_still_picture_header"); + return colorInfo.build(); + } + if (bitArray.readBit()) { // timing_info_present_flag + Log.i(TAG, "Unsupported timing_info_present_flag"); + return colorInfo.build(); + } + if (bitArray.readBit()) { // initial_display_delay_present_flag + Log.i(TAG, "Unsupported initial_display_delay_present_flag"); + return colorInfo.build(); + } + int operatingPointsCountMinus1 = bitArray.readBits(5); // operating_points_cnt_minus_1 + for (int i = 0; i <= operatingPointsCountMinus1; i++) { + bitArray.skipBits(12); // operating_point_idc[i] + int seqLevelIdx = bitArray.readBits(5); // seq_level_idx[i] + if (seqLevelIdx > 7) { + bitArray.skipBit(); // seq_tier[i] + } + } + int frameWidthBitsMinus1 = bitArray.readBits(4); // frame_width_bits_minus_1 + int frameHeightBitsMinus1 = bitArray.readBits(4); // frame_height_bits_minus_1 + bitArray.skipBits(frameWidthBitsMinus1 + 1); // max_frame_width_minus_1 + bitArray.skipBits(frameHeightBitsMinus1 + 1); // max_frame_height_minus_1 + if (bitArray.readBit()) { // frame_id_numbers_present_flag + bitArray.skipBits(7); // delta_frame_id_length_minus_2, additional_frame_id_length_minus_1 + } + bitArray.skipBits(7); // use_128x128_superblock...enable_dual_filter: 7 flags + boolean enableOrderHint = bitArray.readBit(); // enable_order_hint + if (enableOrderHint) { + bitArray.skipBits(2); // enable_jnt_comp, enable_ref_frame_mvs + } + int seqForceScreenContentTools = + bitArray.readBit() // seq_choose_screen_content_tools + ? 2 // SELECT_SCREEN_CONTENT_TOOLS + : bitArray.readBits(1); // seq_force_screen_content_tools + if (seqForceScreenContentTools > 0) { + if (!bitArray.readBit()) { // seq_choose_integer_mv + bitArray.skipBits(1); // seq_force_integer_mv + } + } + if (enableOrderHint) { + bitArray.skipBits(3); // order_hint_bits_minus_1 + } + bitArray.skipBits(3); // enable_superres, enable_cdef, enable_restoration + // 5.5.2. OBU Color config syntax + boolean colorConfigHighBitdepth = bitArray.readBit(); // high_bitdepth + if (obuSeqHeaderSeqProfile == 2 && colorConfigHighBitdepth) { + bitArray.skipBit(); // twelve_bit + } + + boolean monochrome = (obuSeqHeaderSeqProfile != 1) && bitArray.readBit(); // mono_chrome + + if (bitArray.readBit()) { // color_description_present_flag + int colorPrimaries = bitArray.readBits(8); // color_primaries + int transferCharacteristics = bitArray.readBits(8); // transfer_characteristics + int matrixCoefficients = bitArray.readBits(8); // matrix_coefficients + int colorRange = + (!monochrome + && colorPrimaries == 1 // CP_BT_709 + && transferCharacteristics == 13 // TC_SRGB + && matrixCoefficients == 0) // MC_IDENTITY + ? 1 + : bitArray.readBits(1); // color_range; + colorInfo + .setColorSpace(ColorInfo.isoColorPrimariesToColorSpace(colorPrimaries)) + .setColorRange((colorRange == 1) ? C.COLOR_RANGE_FULL : C.COLOR_RANGE_LIMITED) + .setColorTransfer( + ColorInfo.isoTransferCharacteristicsToColorTransfer(transferCharacteristics)); + } + return colorInfo.build(); + } + private static ByteBuffer allocateHdrStaticInfo() { // For HDR static info, Android decoders expect a 25-byte array. The first byte is zero to // represent Static Metadata Type 1, as per CTA-861-G:2017, Table 44. The following 24 bytes @@ -2181,151 +2296,4 @@ import java.util.List; } } } - - /** - * Helper class for parsing syntax elements from AV1 bitstream. - * - *
Bitstream specification: https://aomediacodec.github.io/av1-spec/av1-spec.pdf - */ - private static final class Av1BitstreamParser { - private static final String TAG = "Av1BitstreamParser"; - - public int colorDescriptionPresentFlag; - public int colorPrimaries; - public int transferCharacteristics; - public int matrixCoefficients; - public int colorRange; - - private final ParsableByteArray data; - private int bitCount; - private int currentByte; - private boolean parseSequenceHeaderCalled; - - public Av1BitstreamParser(ParsableByteArray data) { - this.data = data; - } - - /** - * Parses a fixed-length unsigned number. - * - *
See AV1 bitstream spec 4.10.2. f(n): Unsigned n-bit number appearing directly in the - * bitstream. The bits are read from high to low order. - * - * @param length The length (in bits) of the number to decode. - * @return Parsed unsigned number. - */ - private int parseF(int length) { - int result = 0; - while (length > 0) { - if (bitCount == 0) { - currentByte = data.readUnsignedByte(); - bitCount = 8; - } - int newBitCount = min(length, bitCount); - bitCount -= newBitCount; - length -= newBitCount; - result = (result << newBitCount) | ((currentByte >> bitCount) & ((1 << newBitCount) - 1)); - } - return result; - } - - /** - * Parses the AV1 sequence header. - * - *
See AV1 bitstream spec 5.5.1. This method can only be called once. - */ - public boolean parseSequenceHeader() { - if (parseSequenceHeaderCalled) { - return false; - } - parseSequenceHeaderCalled = true; - - // 5.3.1. General OBU syntax - parseF(1); // obu_forbidden_bit - int obuType = parseF(4); // obu_type - if (obuType != 1) { // obu_type != OBU_SEQUENCE_HEADER - Log.e(TAG, "Unsupported obu_type: " + obuType); - return false; - } else if (parseF(1) != 0) { // obu_extension_flag - Log.e(TAG, "Unsupported obu_extension_flag"); - return false; - } - int obuHasSizeField = parseF(1); // obu_has_size_field - parseF(1); // obu_reserved_1bit - if (obuHasSizeField == 1 && parseF(8) > 127) { // obu_size - Log.e(TAG, "Excessive obu_size"); - return false; - } - // 5.5.1. General sequence header OBU syntax - int seqProfile = parseF(3); // seq_profile - parseF(1); // still_picture - if (parseF(1) != 0) { // reduced_still_picture_header - Log.e(TAG, "Unsupported reduced_still_picture_header"); - return false; - } else if (parseF(1) != 0) { // timing_info_present_flag - Log.e(TAG, "Unsupported timing_info_present_flag"); - return false; - } else if (parseF(1) != 0) { // initial_display_delay_present_flag - Log.e(TAG, "Unsupported initial_display_delay_present_flag"); - return false; - } - int operatingPointsCntMinus1 = parseF(5); // operating_points_cnt_minus_1 - for (int i = 0; i <= operatingPointsCntMinus1; i++) { - parseF(12); // operating_point_idc[i] - int seqLevelIdx = parseF(5); // seq_level_idx[i] - if (seqLevelIdx > 7) { - parseF(1); // seq_tier[i] - } - } - int frameWidthBitsMinus1 = parseF(4); // frame_width_bits_minus_1 - int frameHeightBitsMinus1 = parseF(4); // frame_height_bits_minus_1 - parseF(frameWidthBitsMinus1 + 1); // max_frame_width_minus_1 - parseF(frameHeightBitsMinus1 + 1); // max_frame_height_minus_1 - if (parseF(1) == 1) { // frame_id_numbers_present_flag - parseF(7); // delta_frame_id_length_minus_2, additional_frame_id_length_minus_1 - } - parseF(7); // use_128x128_superblock...enable_dual_filter: 7 flags - int enableOrderHint = parseF(1); // enable_order_hint - if (enableOrderHint == 1) { - parseF(2); // enable_jnt_comp, enable_ref_frame_mvs - } - int seqForceScreenContentTools = 2; // SELECT_SCREEN_CONTENT_TOOLS - if (parseF(1) == 0) { // seq_choose_screen_content_tools - seqForceScreenContentTools = parseF(1); // seq_force_screen_content_tools - } - if (seqForceScreenContentTools > 0) { - if (parseF(1) == 0) { // seq_choose_integer_mv - parseF(1); // seq_force_integer_mv - } - } - if (enableOrderHint == 1) { - parseF(3); // order_hint_bits_minus_1 - } - parseF(3); // enable_superres, enable_cdef, enable_restoration - // 5.5.2. Color config syntax - int highBitdepth = parseF(1); // high_bitdepth - if (seqProfile == 2 && highBitdepth == 1) { - parseF(1); // twelve_bit - } - int monoChrome = 0; - if (seqProfile != 1) { - monoChrome = parseF(1); // mono_chrome - } - colorDescriptionPresentFlag = parseF(1); // color_description_present_flag - if (colorDescriptionPresentFlag == 1) { - colorPrimaries = parseF(8); // color_primaries - transferCharacteristics = parseF(8); // transfer_characteristics - matrixCoefficients = parseF(8); // matrix_coefficients - if (monoChrome == 0 - && colorPrimaries == 1 // CP_BT_709 - && transferCharacteristics == 13 // TC_SRGB - && matrixCoefficients == 0) { // MC_IDENTITY - colorRange = 1; - } else { - colorRange = parseF(1); // color_range - } - } - return true; - } - } }