* MLP codec common header file
* Copyright (c) 2007-2008 Ian Caulfield
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#ifndef FFMPEG_MLP_H
-#define FFMPEG_MLP_H
+#ifndef AVCODEC_MLP_H
+#define AVCODEC_MLP_H
#include <stdint.h>
#include "avcodec.h"
-/** Maximum number of channels that can be decoded. */
-#define MAX_CHANNELS 16
+/** Last possible matrix channel for each codec */
+#define MAX_MATRIX_CHANNEL_MLP 5
+#define MAX_MATRIX_CHANNEL_TRUEHD 7
+/** Maximum number of channels in a valid stream.
+ * MLP : 5.1 + 2 noise channels -> 8 channels
+ * TrueHD: 7.1 -> 8 channels
+ */
+#define MAX_CHANNELS 8
/** Maximum number of matrices used in decoding; most streams have one matrix
* per output channel, but some rematrix a channel (usually 0) more than once.
*/
+#define MAX_MATRICES_MLP 6
+#define MAX_MATRICES_TRUEHD 8
+#define MAX_MATRICES 8
-#define MAX_MATRICES 15
-
-/** Maximum number of substreams that can be decoded. This could also be set
- * higher, but I haven't seen any examples with more than two. */
-#define MAX_SUBSTREAMS 2
+/** Maximum number of substreams that can be decoded.
+ * MLP's limit is 2. TrueHD supports at least up to 3.
+ */
+#define MAX_SUBSTREAMS 3
+/** which multiple of 48000 the maximum sample rate is */
+#define MAX_RATEFACTOR 4
/** maximum sample frequency seen in files */
-#define MAX_SAMPLERATE 192000
+#define MAX_SAMPLERATE (MAX_RATEFACTOR * 48000)
/** maximum number of audio samples within one access unit */
-#define MAX_BLOCKSIZE (40 * (MAX_SAMPLERATE / 48000))
+#define MAX_BLOCKSIZE (40 * MAX_RATEFACTOR)
/** next power of two greater than MAX_BLOCKSIZE */
-#define MAX_BLOCKSIZE_POW2 (64 * (MAX_SAMPLERATE / 48000))
+#define MAX_BLOCKSIZE_POW2 (64 * MAX_RATEFACTOR)
/** number of allowed filters */
#define NUM_FILTERS 2
-/** The maximum number of taps in either the IIR or FIR filter;
- * I believe MLP actually specifies the maximum order for IIR filters as four,
- * and that the sum of the orders of both filters must be <= 8. */
-#define MAX_FILTER_ORDER 8
+/** The maximum number of taps in IIR and FIR filters. */
+#define MAX_FIR_ORDER 8
+#define MAX_IIR_ORDER 4
+
+/** Code that signals end of a stream. */
+#define END_OF_STREAM 0xd234d234
#define FIR 0
#define IIR 1
/** filter data */
-typedef struct {
+typedef struct FilterParams {
uint8_t order; ///< number of taps in filter
uint8_t shift; ///< Right shift to apply to output of filter.
- int32_t coeff[MAX_FILTER_ORDER];
- int32_t state[MAX_FILTER_ORDER];
+ int32_t state[MAX_FIR_ORDER];
} FilterParams;
/** sample data coding information */
-typedef struct {
+typedef struct ChannelParams {
FilterParams filter_params[NUM_FILTERS];
+ int32_t coeff[NUM_FILTERS][MAX_FIR_ORDER];
int16_t huff_offset; ///< Offset to apply to residual values.
int32_t sign_huff_offset; ///< sign/rounding-corrected version of huff_offset
/** Tables defining the Huffman codes.
* There are three entropy coding methods used in MLP (four if you count
* "none" as a method). These use the same sequences for codes starting with
- * 00 or 01, but have different codes starting with 1. */
-
+ * 00 or 01, but have different codes starting with 1.
+ */
extern const uint8_t ff_mlp_huffman_tables[3][18][2];
/** MLP uses checksums that seem to be based on the standard CRC algorithm, but
* are not (in implementation terms, the table lookup and XOR are reversed).
* We can implement this behavior using a standard av_crc on all but the
- * last element, then XOR that with the last element. */
-
+ * last element, then XOR that with the last element.
+ */
uint8_t ff_mlp_checksum8 (const uint8_t *buf, unsigned int buf_size);
uint16_t ff_mlp_checksum16(const uint8_t *buf, unsigned int buf_size);
/** Calculate an 8-bit checksum over a restart header -- a non-multiple-of-8
- * number of bits, starting two bits into the first byte of buf. */
-
+ * number of bits, starting two bits into the first byte of buf.
+ */
uint8_t ff_mlp_restart_checksum(const uint8_t *buf, unsigned int bit_size);
/** XOR together all the bytes of a buffer.
- * Does this belong in dspcontext? */
-
+ * Does this belong in dspcontext?
+ */
uint8_t ff_mlp_calculate_parity(const uint8_t *buf, unsigned int buf_size);
-int ff_mlp_init_crc2D(AVCodecParserContext *s);
+void ff_mlp_init_crc(void);
-void ff_mlp_init_crc();
+/** XOR four bytes into one. */
+static inline uint8_t xor_32_to_8(uint32_t value)
+{
+ value ^= value >> 16;
+ value ^= value >> 8;
+ return value;
+}
-#endif /* FFMPEG_MLP_H */
+#endif /* AVCODEC_MLP_H */