1 files changed, 175 insertions, 0 deletions

diff --git a/lib/rbcodec/codecs/libmusepack/mpc_bits_reader.h b/lib/rbcodec/codecs/libmusepack/mpc_bits_reader.h
new file mode 100644
index 0000000000..1233720c74
--- /dev/null
+++ b/lib/rbcodec/codecs/libmusepack/mpc_bits_reader.h
@@ -0,0 +1,175 @@
+/*
+  Copyright (c) 2007-2009, The Musepack Development Team
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are
+  met:
+
+  * Redistributions of source code must retain the above copyright
+  notice, this list of conditions and the following disclaimer.
+
+  * Redistributions in binary form must reproduce the above
+  copyright notice, this list of conditions and the following
+  disclaimer in the documentation and/or other materials provided
+  with the distribution.
+
+  * Neither the name of the The Musepack Development Team nor the
+  names of its contributors may be used to endorse or promote
+  products derived from this software without specific prior
+  written permission.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#define MAX_ENUM 32
+
+MPC_API int mpc_bits_get_block(mpc_bits_reader * r, mpc_block * p_block);
+mpc_int32_t mpc_bits_golomb_dec(mpc_bits_reader * r, const mpc_uint_t k);
+MPC_API unsigned int mpc_bits_get_size(mpc_bits_reader * r, mpc_uint64_t * p_size);
+mpc_uint32_t mpc_bits_log_dec(mpc_bits_reader * r, mpc_uint_t max);
+
+extern const mpc_uint32_t Cnk     [MAX_ENUM / 2][MAX_ENUM];
+extern const mpc_uint8_t  Cnk_len [MAX_ENUM / 2][MAX_ENUM];
+extern const mpc_uint32_t Cnk_lost[MAX_ENUM / 2][MAX_ENUM];
+
+// can read up to 31 bits
+static mpc_inline mpc_uint32_t mpc_bits_read(mpc_bits_reader * r, const unsigned int nb_bits)
+{
+    mpc_uint32_t ret;
+
+    r->buff -= (int)(r->count - nb_bits) >> 3;
+    r->count = (r->count - nb_bits) & 0x07;
+
+    ret = (r->buff[0] | (r->buff[-1] << 8)) >> r->count;
+    if (nb_bits > (16 - r->count)) {
+        ret |= (mpc_uint32_t)((r->buff[-2] << 16) | (r->buff[-3] << 24)) >> r->count;
+        if (nb_bits > 24 && r->count != 0)
+            ret |= r->buff[-4] << (32 - r->count);
+    }
+
+    return ret & ((1 << nb_bits) - 1);
+}
+
+#if defined(CPU_COLDFIRE)
+/* rockbox: This is specific code to optimize demux performance on Coldfire
+ * CPUs. Coldfire CPUs are very sensible to RAM accesses. As the bitstream
+ * buffer does not fit into IRAM the read accesses to the uint8 buffer are very
+ * expensive in terms of CPU cycles.
+ * The following code uses two variables in IRAM. The variable last_code keeps
+ * the 4-byte value of buf[0]<<16 | buf[1]<<8 | buf[2]. As long as buf[0] will 
+ * read from the same address the following code will avoid re-reading of the 
+ * buffers. If buf[0] did advance to the next uint8-entry since the last call
+ * the following will only need to load 1 uint8-entry instead of 3. 
+ */
+static mpc_inline mpc_uint16_t get_code_from_buffer(mpc_bits_reader *r)
+{
+    /* Buffer advanced by 1 entry since last call */
+    if (r->buff == r->buffered_addr + 1) {
+        r->buffered_code = (r->buffered_code<<8) | r->buff[2];
+        r->buffered_addr = r->buff;
+    }
+    /* Buffer must be fully re-read */
+    else if (r->buff != r->buffered_addr) {
+        r->buffered_code = (r->buff[0] << 16) | (r->buff[1] << 8) | r->buff[2];
+        r->buffered_addr = r->buff;
+    }
+
+    return (mpc_uint16_t)((r->buffered_code >> r->count) & 0xFFFF);
+}
+#else
+/* Use the decoder's default implementation. This is faster on non-Coldfire targets */
+#define get_code_from_buffer(r) (mpc_uint16_t)((((r->buff[0] << 16) | (r->buff[1] << 8) | r->buff[2]) >> r->count) & 0xFFFF);
+#endif
+
+// basic huffman decoding routine
+// works with maximum lengths up to 16
+static mpc_inline mpc_int32_t mpc_bits_huff_dec(mpc_bits_reader * r, const mpc_huffman *Table)
+{
+    const mpc_uint16_t code = get_code_from_buffer(r);
+
+    while (code < Table->Code) Table++;
+
+    r->buff -= (int)(r->count - Table->Length) >> 3;
+    r->count = (r->count - Table->Length) & 0x07;
+
+    return Table->Value;
+}
+
+static mpc_inline mpc_int32_t mpc_bits_can_dec(mpc_bits_reader * r, const mpc_can_data *can)
+{
+    const mpc_uint16_t code = get_code_from_buffer(r);
+    const mpc_huff_lut tmp  = can->lut[code >> (16 - LUT_DEPTH)];
+    const mpc_huffman * Table;
+
+    if (tmp.Length != 0) {
+        r->buff -= (int)(r->count - tmp.Length) >> 3;
+        r->count = (r->count - tmp.Length) & 0x07;
+        return tmp.Value;
+    }
+
+    Table = can->table + (unsigned char)tmp.Value;
+    while (code < Table->Code) Table++;
+
+    r->buff -= (int)(r->count - Table->Length) >> 3;
+    r->count = (r->count - Table->Length) & 0x07;
+
+    return can->sym[(Table->Value - (code >> (16 - Table->Length))) & 0xFF] ;
+}
+
+// LUT-based huffman decoding routine
+// works with maximum lengths up to 16
+static mpc_inline mpc_int32_t mpc_bits_huff_lut(mpc_bits_reader * r, const mpc_lut_data *lut)
+{
+    const mpc_uint16_t code = get_code_from_buffer(r);
+    const mpc_huff_lut tmp  = lut->lut[code >> (16 - LUT_DEPTH)];
+    const mpc_huffman * Table;
+
+    if (tmp.Length != 0) {
+        r->buff -= (int)(r->count - tmp.Length) >> 3;
+        r->count = (r->count - tmp.Length) & 0x07;
+        return tmp.Value;
+    }
+
+    Table = lut->table + (unsigned char)tmp.Value;
+    while (code < Table->Code) Table++;
+
+    r->buff -= (int)(r->count - Table->Length) >> 3;
+    r->count = (r->count - Table->Length) & 0x07;
+
+    return Table->Value;
+}
+
+static mpc_inline mpc_uint32_t mpc_bits_enum_dec(mpc_bits_reader * r, mpc_uint_t k, mpc_uint_t n)
+{
+    mpc_uint32_t bits = 0;
+    mpc_uint32_t code;
+    const mpc_uint32_t * C = Cnk[k-1];
+
+    code = mpc_bits_read(r, Cnk_len[k-1][n-1] - 1);
+
+    if (code >= Cnk_lost[k-1][n-1])
+        code = ((code << 1) | mpc_bits_read(r, 1)) - Cnk_lost[k-1][n-1];
+
+    do {
+        n--;
+        if (code >= C[n]) {
+            bits |= 1 << n;
+            code -= C[n];
+            C -= MAX_ENUM;
+            k--;
+        }
+    } while(k > 0);
+
+    return bits;
+}