From 386d609dc513e838c7e7c4c46c604493ccd560be Mon Sep 17 00:00:00 2001 From: Andreas Huber Date: Thu, 19 May 2011 08:37:39 -0700 Subject: Support mpeg1,2 audio and mpeg1,2,4 video content extraction from .ts streams. Change-Id: I9d2ee63495f161e30daba7c3aab16cb9d8ced6a5 --- media/libstagefright/avc_utils.cpp | 231 +++++++++++++++++++++++++++++++++++++ 1 file changed, 231 insertions(+) (limited to 'media/libstagefright/avc_utils.cpp') diff --git a/media/libstagefright/avc_utils.cpp b/media/libstagefright/avc_utils.cpp index 95cf2d3..020e947 100644 --- a/media/libstagefright/avc_utils.cpp +++ b/media/libstagefright/avc_utils.cpp @@ -376,5 +376,236 @@ sp MakeAACCodecSpecificData( return meta; } +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 */); + + unsigned video_object_layer_verid; + unsigned video_object_layer_priority; + if (br.getBits(1)) { + video_object_layer_verid = br.getBits(4); + video_object_layer_priority = br.getBits(3); + } + 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 + + unsigned interlaced = br.getBits(1); + + *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; + } + + unsigned protection = (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 = 576; + } + } + + if (out_bitrate) { + *out_bitrate = bitrate; + } + + if (version == 3 /* V1 */) { + *frame_size = 144000 * bitrate / sampling_rate + padding; + } else { + // V2 or V2.5 + *frame_size = 72000 * 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 -- cgit v1.1