/* * Copyright (C) 2010 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. */ //#define LOG_NDEBUG 0 #define LOG_TAG "avc_utils" #include #include #include #include #include #include #include #include #include namespace android { unsigned parseUE(ABitReader *br) { unsigned numZeroes = 0; while (br->getBits(1) == 0) { ++numZeroes; } unsigned x = br->getBits(numZeroes); return x + (1u << numZeroes) - 1; } unsigned parseUEWithFallback(ABitReader *br, unsigned fallback) { unsigned numZeroes = 0; while (br->getBitsWithFallback(1, 1) == 0) { ++numZeroes; } uint32_t x; if (numZeroes < 32) { if (br->getBitsGraceful(numZeroes, &x)) { return x + (1u << numZeroes) - 1; } else { return fallback; } } else { br->skipBits(numZeroes); return fallback; } } signed parseSE(ABitReader *br) { unsigned codeNum = parseUE(br); return (codeNum & 1) ? (codeNum + 1) / 2 : -signed(codeNum / 2); } signed parseSEWithFallback(ABitReader *br, signed fallback) { // NOTE: parseUE cannot normally return ~0 as the max supported value is 0xFFFE unsigned codeNum = parseUEWithFallback(br, ~0U); if (codeNum == ~0U) { return fallback; } return (codeNum & 1) ? (codeNum + 1) / 2 : -signed(codeNum / 2); } static void skipScalingList(ABitReader *br, size_t sizeOfScalingList) { size_t lastScale = 8; size_t nextScale = 8; for (size_t j = 0; j < sizeOfScalingList; ++j) { if (nextScale != 0) { signed delta_scale = parseSE(br); // ISO_IEC_14496-10_201402-ITU, 7.4.2.1.1.1, The value of delta_scale // shall be in the range of −128 to +127, inclusive. if (delta_scale < -128) { ALOGW("delta_scale (%d) is below range, capped to -128", delta_scale); delta_scale = -128; } else if (delta_scale > 127) { ALOGW("delta_scale (%d) is above range, capped to 127", delta_scale); delta_scale = 127; } nextScale = (lastScale + (delta_scale + 256)) % 256; } lastScale = (nextScale == 0) ? lastScale : nextScale; } } // Determine video dimensions from the sequence parameterset. void FindAVCDimensions( const sp &seqParamSet, int32_t *width, int32_t *height, int32_t *sarWidth, int32_t *sarHeight) { ABitReader br(seqParamSet->data() + 1, seqParamSet->size() - 1); unsigned profile_idc = br.getBits(8); br.skipBits(16); parseUE(&br); // seq_parameter_set_id unsigned chroma_format_idc = 1; // 4:2:0 chroma format if (profile_idc == 100 || profile_idc == 110 || profile_idc == 122 || profile_idc == 244 || profile_idc == 44 || profile_idc == 83 || profile_idc == 86) { chroma_format_idc = parseUE(&br); if (chroma_format_idc == 3) { br.skipBits(1); // residual_colour_transform_flag } parseUE(&br); // bit_depth_luma_minus8 parseUE(&br); // bit_depth_chroma_minus8 br.skipBits(1); // qpprime_y_zero_transform_bypass_flag if (br.getBits(1)) { // seq_scaling_matrix_present_flag for (size_t i = 0; i < 8; ++i) { if (br.getBits(1)) { // seq_scaling_list_present_flag[i] // WARNING: the code below has not ever been exercised... // need a real-world example. if (i < 6) { // ScalingList4x4[i],16,... skipScalingList(&br, 16); } else { // ScalingList8x8[i-6],64,... skipScalingList(&br, 64); } } } } } parseUE(&br); // log2_max_frame_num_minus4 unsigned pic_order_cnt_type = parseUE(&br); if (pic_order_cnt_type == 0) { parseUE(&br); // log2_max_pic_order_cnt_lsb_minus4 } else if (pic_order_cnt_type == 1) { // offset_for_non_ref_pic, offset_for_top_to_bottom_field and // offset_for_ref_frame are technically se(v), but since we are // just skipping over them the midpoint does not matter. br.getBits(1); // delta_pic_order_always_zero_flag parseUE(&br); // offset_for_non_ref_pic parseUE(&br); // offset_for_top_to_bottom_field unsigned num_ref_frames_in_pic_order_cnt_cycle = parseUE(&br); for (unsigned i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; ++i) { parseUE(&br); // offset_for_ref_frame } } parseUE(&br); // num_ref_frames br.getBits(1); // gaps_in_frame_num_value_allowed_flag unsigned pic_width_in_mbs_minus1 = parseUE(&br); unsigned pic_height_in_map_units_minus1 = parseUE(&br); unsigned frame_mbs_only_flag = br.getBits(1); // *width = pic_width_in_mbs_minus1 * 16 + 16; if (__builtin_mul_overflow(pic_width_in_mbs_minus1, 16, &pic_width_in_mbs_minus1) || __builtin_add_overflow(pic_width_in_mbs_minus1, 16, width)) { *width = 0; } // *height = (2 - frame_mbs_only_flag) * (pic_height_in_map_units_minus1 * 16 + 16); if (__builtin_mul_overflow( pic_height_in_map_units_minus1, 16, &pic_height_in_map_units_minus1) || __builtin_add_overflow( pic_height_in_map_units_minus1, 16, &pic_height_in_map_units_minus1) || __builtin_mul_overflow( pic_height_in_map_units_minus1, (2 - frame_mbs_only_flag), height)) { *height = 0; } if (!frame_mbs_only_flag) { br.getBits(1); // mb_adaptive_frame_field_flag } br.getBits(1); // direct_8x8_inference_flag if (br.getBits(1)) { // frame_cropping_flag unsigned frame_crop_left_offset = parseUE(&br); unsigned frame_crop_right_offset = parseUE(&br); unsigned frame_crop_top_offset = parseUE(&br); unsigned frame_crop_bottom_offset = parseUE(&br); unsigned cropUnitX, cropUnitY; if (chroma_format_idc == 0 /* monochrome */) { cropUnitX = 1; cropUnitY = 2 - frame_mbs_only_flag; } else { unsigned subWidthC = (chroma_format_idc == 3) ? 1 : 2; unsigned subHeightC = (chroma_format_idc == 1) ? 2 : 1; cropUnitX = subWidthC; cropUnitY = subHeightC * (2 - frame_mbs_only_flag); } ALOGV("frame_crop = (%u, %u, %u, %u), cropUnitX = %u, cropUnitY = %u", frame_crop_left_offset, frame_crop_right_offset, frame_crop_top_offset, frame_crop_bottom_offset, cropUnitX, cropUnitY); // *width -= (frame_crop_left_offset + frame_crop_right_offset) * cropUnitX; if(__builtin_add_overflow( frame_crop_left_offset, frame_crop_right_offset, &frame_crop_left_offset) || __builtin_mul_overflow(frame_crop_left_offset, cropUnitX, &frame_crop_left_offset) || __builtin_sub_overflow(*width, frame_crop_left_offset, width) || *width < 0) { *width = 0; } //*height -= (frame_crop_top_offset + frame_crop_bottom_offset) * cropUnitY; if(__builtin_add_overflow( frame_crop_top_offset, frame_crop_bottom_offset, &frame_crop_top_offset) || __builtin_mul_overflow(frame_crop_top_offset, cropUnitY, &frame_crop_top_offset) || __builtin_sub_overflow(*height, frame_crop_top_offset, height) || *height < 0) { *height = 0; } } if (sarWidth != NULL) { *sarWidth = 0; } if (sarHeight != NULL) { *sarHeight = 0; } if (br.getBits(1)) { // vui_parameters_present_flag unsigned sar_width = 0, sar_height = 0; if (br.getBits(1)) { // aspect_ratio_info_present_flag unsigned aspect_ratio_idc = br.getBits(8); if (aspect_ratio_idc == 255 /* extendedSAR */) { sar_width = br.getBits(16); sar_height = br.getBits(16); } else { static const struct { unsigned width, height; } kFixedSARs[] = { { 0, 0 }, // Invalid { 1, 1 }, { 12, 11 }, { 10, 11 }, { 16, 11 }, { 40, 33 }, { 24, 11 }, { 20, 11 }, { 32, 11 }, { 80, 33 }, { 18, 11 }, { 15, 11 }, { 64, 33 }, { 160, 99 }, { 4, 3 }, { 3, 2 }, { 2, 1 }, }; if (aspect_ratio_idc > 0 && aspect_ratio_idc < NELEM(kFixedSARs)) { sar_width = kFixedSARs[aspect_ratio_idc].width; sar_height = kFixedSARs[aspect_ratio_idc].height; } } } ALOGV("sample aspect ratio = %u : %u", sar_width, sar_height); if (sarWidth != NULL) { *sarWidth = sar_width; } if (sarHeight != NULL) { *sarHeight = sar_height; } } } status_t getNextNALUnit( const uint8_t **_data, size_t *_size, const uint8_t **nalStart, size_t *nalSize, bool startCodeFollows) { const uint8_t *data = *_data; size_t size = *_size; *nalStart = NULL; *nalSize = 0; if (size < 3) { return -EAGAIN; } size_t offset = 0; // A valid startcode consists of at least two 0x00 bytes followed by 0x01. for (; offset + 2 < size; ++offset) { if (data[offset + 2] == 0x01 && data[offset] == 0x00 && data[offset + 1] == 0x00) { break; } } if (offset + 2 >= size) { *_data = &data[offset]; *_size = 2; return -EAGAIN; } offset += 3; size_t startOffset = offset; for (;;) { while (offset < size && data[offset] != 0x01) { ++offset; } if (offset == size) { if (startCodeFollows) { offset = size + 2; break; } return -EAGAIN; } if (data[offset - 1] == 0x00 && data[offset - 2] == 0x00) { break; } ++offset; } size_t endOffset = offset - 2; while (endOffset > startOffset + 1 && data[endOffset - 1] == 0x00) { --endOffset; } *nalStart = &data[startOffset]; *nalSize = endOffset - startOffset; if (offset + 2 < size) { *_data = &data[offset - 2]; *_size = size - offset + 2; } else { *_data = NULL; *_size = 0; } return OK; } static sp FindNAL(const uint8_t *data, size_t size, unsigned nalType) { const uint8_t *nalStart; size_t nalSize; while (getNextNALUnit(&data, &size, &nalStart, &nalSize, true) == OK) { if (nalSize > 0 && (nalStart[0] & 0x1f) == nalType) { sp buffer = new ABuffer(nalSize); memcpy(buffer->data(), nalStart, nalSize); return buffer; } } return NULL; } const char *AVCProfileToString(uint8_t profile) { switch (profile) { case kAVCProfileBaseline: return "Baseline"; case kAVCProfileMain: return "Main"; case kAVCProfileExtended: return "Extended"; case kAVCProfileHigh: return "High"; case kAVCProfileHigh10: return "High 10"; case kAVCProfileHigh422: return "High 422"; case kAVCProfileHigh444: return "High 444"; case kAVCProfileCAVLC444Intra: return "CAVLC 444 Intra"; default: return "Unknown"; } } sp MakeAVCCodecSpecificData( const sp &accessUnit, int32_t *width, int32_t *height, int32_t *sarWidth, int32_t *sarHeight) { const uint8_t *data = accessUnit->data(); size_t size = accessUnit->size(); sp seqParamSet = FindNAL(data, size, 7); if (seqParamSet == NULL) { return NULL; } FindAVCDimensions( seqParamSet, width, height, sarWidth, sarHeight); sp picParamSet = FindNAL(data, size, 8); CHECK(picParamSet != NULL); size_t csdSize = 1 + 3 + 1 + 1 + 2 * 1 + seqParamSet->size() + 1 + 2 * 1 + picParamSet->size(); sp csd = new ABuffer(csdSize); uint8_t *out = csd->data(); *out++ = 0x01; // configurationVersion memcpy(out, seqParamSet->data() + 1, 3); // profile/level... uint8_t profile = out[0]; uint8_t level = out[2]; out += 3; *out++ = (0x3f << 2) | 1; // lengthSize == 2 bytes *out++ = 0xe0 | 1; *out++ = seqParamSet->size() >> 8; *out++ = seqParamSet->size() & 0xff; memcpy(out, seqParamSet->data(), seqParamSet->size()); out += seqParamSet->size(); *out++ = 1; *out++ = picParamSet->size() >> 8; *out++ = picParamSet->size() & 0xff; memcpy(out, picParamSet->data(), picParamSet->size()); #if 0 ALOGI("AVC seq param set"); hexdump(seqParamSet->data(), seqParamSet->size()); #endif if (sarWidth != nullptr && sarHeight != nullptr) { if ((*sarWidth > 0 && *sarHeight > 0) && (*sarWidth != 1 || *sarHeight != 1)) { ALOGI("found AVC codec config (%d x %d, %s-profile level %d.%d) " "SAR %d : %d", *width, *height, AVCProfileToString(profile), level / 10, level % 10, *sarWidth, *sarHeight); } else { // We treat *:0 and 0:* (unspecified) as 1:1. *sarWidth = 0; *sarHeight = 0; ALOGI("found AVC codec config (%d x %d, %s-profile level %d.%d)", *width, *height, AVCProfileToString(profile), level / 10, level % 10); } } return csd; } bool IsIDR(const uint8_t *data, size_t size) { // const uint8_t *data = buffer->data(); // size_t size = buffer->size(); bool foundIDR = false; const uint8_t *nalStart; size_t nalSize; while (getNextNALUnit(&data, &size, &nalStart, &nalSize, true) == OK) { if (nalSize == 0u) { ALOGW("skipping empty nal unit from potentially malformed bitstream"); continue; } unsigned nalType = nalStart[0] & 0x1f; if (nalType == 5) { foundIDR = true; break; } } return foundIDR; } bool IsAVCReferenceFrame(const sp &accessUnit) { const uint8_t *data = accessUnit->data(); size_t size = accessUnit->size(); if (data == NULL) { ALOGE("IsAVCReferenceFrame: called on NULL data (%p, %zu)", accessUnit.get(), size); return false; } const uint8_t *nalStart; size_t nalSize; while (getNextNALUnit(&data, &size, &nalStart, &nalSize, true) == OK) { if (nalSize == 0) { ALOGE("IsAVCReferenceFrame: invalid nalSize: 0 (%p, %zu)", accessUnit.get(), size); return false; } unsigned nalType = nalStart[0] & 0x1f; if (nalType == 5) { return true; } else if (nalType == 1) { unsigned nal_ref_idc = (nalStart[0] >> 5) & 3; return nal_ref_idc != 0; } } return true; } uint32_t FindAVCLayerId(const uint8_t *data, size_t size) { CHECK(data != NULL); const unsigned kSvcNalType = 0xE; const unsigned kSvcNalSearchRange = 32; // SVC NAL // |---0 1110|1--- ----|---- ----|iii- ---| // ^ ^ // NAL-type = 0xE layer-Id // // layer_id 0 is for base layer, while 1, 2, ... are enhancement layers. // Layer n uses reference frames from layer 0, 1, ..., n-1. uint32_t layerId = 0; sp svcNAL = FindNAL( data, size > kSvcNalSearchRange ? kSvcNalSearchRange : size, kSvcNalType); if (svcNAL != NULL && svcNAL->size() >= 4) { layerId = (*(svcNAL->data() + 3) >> 5) & 0x7; } return layerId; } bool ExtractDimensionsFromVOLHeader( const uint8_t *data, size_t size, int32_t *width, int32_t *height) { ABitReader br(&data[4], size - 4); br.skipBits(1); // random_accessible_vol unsigned video_object_type_indication = br.getBits(8); CHECK_NE(video_object_type_indication, 0x21u /* Fine Granularity Scalable */); if (br.getBits(1)) { br.skipBits(4); //video_object_layer_verid br.skipBits(3); //video_object_layer_priority } unsigned aspect_ratio_info = br.getBits(4); if (aspect_ratio_info == 0x0f /* extended PAR */) { br.skipBits(8); // par_width br.skipBits(8); // par_height } if (br.getBits(1)) { // vol_control_parameters br.skipBits(2); // chroma_format br.skipBits(1); // low_delay if (br.getBits(1)) { // vbv_parameters br.skipBits(15); // first_half_bit_rate CHECK(br.getBits(1)); // marker_bit br.skipBits(15); // latter_half_bit_rate CHECK(br.getBits(1)); // marker_bit br.skipBits(15); // first_half_vbv_buffer_size CHECK(br.getBits(1)); // marker_bit br.skipBits(3); // latter_half_vbv_buffer_size br.skipBits(11); // first_half_vbv_occupancy CHECK(br.getBits(1)); // marker_bit br.skipBits(15); // latter_half_vbv_occupancy CHECK(br.getBits(1)); // marker_bit } } unsigned video_object_layer_shape = br.getBits(2); CHECK_EQ(video_object_layer_shape, 0x00u /* rectangular */); CHECK(br.getBits(1)); // marker_bit unsigned vop_time_increment_resolution = br.getBits(16); CHECK(br.getBits(1)); // marker_bit if (br.getBits(1)) { // fixed_vop_rate // range [0..vop_time_increment_resolution) // vop_time_increment_resolution // 2 => 0..1, 1 bit // 3 => 0..2, 2 bits // 4 => 0..3, 2 bits // 5 => 0..4, 3 bits // ... CHECK_GT(vop_time_increment_resolution, 0u); --vop_time_increment_resolution; unsigned numBits = 0; while (vop_time_increment_resolution > 0) { ++numBits; vop_time_increment_resolution >>= 1; } br.skipBits(numBits); // fixed_vop_time_increment } CHECK(br.getBits(1)); // marker_bit unsigned video_object_layer_width = br.getBits(13); CHECK(br.getBits(1)); // marker_bit unsigned video_object_layer_height = br.getBits(13); CHECK(br.getBits(1)); // marker_bit br.skipBits(1); // interlaced *width = video_object_layer_width; *height = video_object_layer_height; return true; } bool GetMPEGAudioFrameSize( uint32_t header, size_t *frame_size, int *out_sampling_rate, int *out_channels, int *out_bitrate, int *out_num_samples) { *frame_size = 0; if (out_sampling_rate) { *out_sampling_rate = 0; } if (out_channels) { *out_channels = 0; } if (out_bitrate) { *out_bitrate = 0; } if (out_num_samples) { *out_num_samples = 1152; } if ((header & 0xffe00000) != 0xffe00000) { return false; } unsigned version = (header >> 19) & 3; if (version == 0x01) { return false; } unsigned layer = (header >> 17) & 3; if (layer == 0x00) { return false; } // we can get protection value from (header >> 16) & 1 unsigned bitrate_index = (header >> 12) & 0x0f; if (bitrate_index == 0 || bitrate_index == 0x0f) { // Disallow "free" bitrate. return false; } unsigned sampling_rate_index = (header >> 10) & 3; if (sampling_rate_index == 3) { return false; } static const int kSamplingRateV1[] = { 44100, 48000, 32000 }; int sampling_rate = kSamplingRateV1[sampling_rate_index]; if (version == 2 /* V2 */) { sampling_rate /= 2; } else if (version == 0 /* V2.5 */) { sampling_rate /= 4; } unsigned padding = (header >> 9) & 1; if (layer == 3) { // layer I static const int kBitrateV1[] = { 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448 }; static const int kBitrateV2[] = { 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256 }; int bitrate = (version == 3 /* V1 */) ? kBitrateV1[bitrate_index - 1] : kBitrateV2[bitrate_index - 1]; if (out_bitrate) { *out_bitrate = bitrate; } *frame_size = (12000 * bitrate / sampling_rate + padding) * 4; if (out_num_samples) { *out_num_samples = 384; } } else { // layer II or III static const int kBitrateV1L2[] = { 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384 }; static const int kBitrateV1L3[] = { 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320 }; static const int kBitrateV2[] = { 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160 }; int bitrate; if (version == 3 /* V1 */) { bitrate = (layer == 2 /* L2 */) ? kBitrateV1L2[bitrate_index - 1] : kBitrateV1L3[bitrate_index - 1]; if (out_num_samples) { *out_num_samples = 1152; } } else { // V2 (or 2.5) bitrate = kBitrateV2[bitrate_index - 1]; if (out_num_samples) { *out_num_samples = (layer == 1 /* L3 */) ? 576 : 1152; } } if (out_bitrate) { *out_bitrate = bitrate; } if (version == 3 /* V1 */) { *frame_size = 144000 * bitrate / sampling_rate + padding; } else { // V2 or V2.5 size_t tmp = (layer == 1 /* L3 */) ? 72000 : 144000; *frame_size = tmp * bitrate / sampling_rate + padding; } } if (out_sampling_rate) { *out_sampling_rate = sampling_rate; } if (out_channels) { int channel_mode = (header >> 6) & 3; *out_channels = (channel_mode == 3) ? 1 : 2; } return true; } } // namespace android