Cooking since 2014-04-22.
* t/bitstream_improvements:
bitstream: Improve documentation.
wma: Store ASF header info in afhi->techinfo.
bitstream: Replace check for impossible condition by assertion.
bitstream: Remove pointless variable "code_prefix2".
bitstream: Micro-optimization.
bitstream: Kill pointless variable "symbol".
bitstream: Trivial coding style fixes.
bitstream: Trivial spelling fix auxillary -> auxiliary.
- ao_writer fixes. This writer was in a quite bad shape. Many
serious bugs have been fixed.
- new audiod command: version.
+ - Minor improvements to the bitstream API.
+
----------------------------------------
0.5.2 (2014-04-11) "orthogonal interior"
* For licencing details see COPYING.LIB.
*/
-/**
- * \file bitstream.c Bitstream API.
- */
+/** \file bitstream.c Bitstream API for the wma decoder. */
#include <stdlib.h>
#include <inttypes.h>
const void *bits, const void *codes, int codes_size,
uint32_t code_prefix, int n_prefix)
{
- int i, j, k, n, table_size, table_index, nb, n1, idx, code_prefix2,
- symbol;
+ int i, j, k, n, table_size, table_index, nb, n1, idx;
uint32_t code;
VLC_TYPE(*table)[2];
table = &vlc->table[table_index];
for (i = 0; i < table_size; i++) {
- table[i][1] = 0; //bits
- table[i][0] = -1; //codes
+ table[i][1] = 0; /* bits */
+ table[i][0] = -1; /* codes */
}
- /* map codes and compute auxillary table sizes */
+ /* map codes and compute auxiliary table sizes */
for (i = 0; i < nb_codes; i++) {
GET_DATA(n, bits, i, 1);
- GET_DATA(code, codes, i, codes_size);
/* we accept tables with holes */
+ n -= n_prefix;
if (n <= 0)
continue;
- symbol = i;
+ GET_DATA(code, codes, i, codes_size);
/* if code matches the prefix, it is in the table */
- n -= n_prefix;
- code_prefix2 = code >> n;
- if (n <= 0 || code_prefix2 != code_prefix)
+ if ((code >> n) != code_prefix)
continue;
if (n <= table_nb_bits) {
/* no need to add another table */
j = (code << (table_nb_bits - n)) & (table_size - 1);
nb = 1 << (table_nb_bits - n);
for (k = 0; k < nb; k++) {
- if (table[j][1] /* bits */ != 0) {
- PARA_EMERG_LOG("incorrect code\n");
- exit(EXIT_FAILURE);
- }
- table[j][1] = n; //bits
- table[j][0] = symbol;
+ assert(table[j][1] == 0); /* incorrect code */
+ table[j][1] = n; /* bits */
+ table[j][0] = i;
j++;
}
} else {
n -= table_nb_bits;
j = (code >> n) & ((1 << table_nb_bits) - 1);
/* compute table size */
- n1 = -table[j][1]; //bits
+ n1 = -table[j][1]; /* bits */
if (n > n1)
n1 = n;
- table[j][1] = -n1; //bits
+ table[j][1] = -n1; /* bits */
}
}
- /* fill auxillary tables recursively */
+ /* fill auxiliary tables recursively */
for (i = 0; i < table_size; i++) {
- n = table[i][1]; //bits
+ n = table[i][1]; /* bits */
if (n < 0) {
n = -n;
if (n > table_nb_bits) {
n = table_nb_bits;
- table[i][1] = -n; //bits
+ table[i][1] = -n; /* bits */
}
idx = build_table(vlc, n, nb_codes, bits, codes,
codes_size, (code_prefix << table_nb_bits) | i,
n_prefix + table_nb_bits);
/* vlc->table might have changed */
table = &vlc->table[table_index];
- table[i][0] = idx; //code
+ table[i][0] = idx; /* code */
}
}
return table_index;
* Build VLC decoding tables suitable for use with get_vlc().
*
* \param vlc The structure to be initialized.
- *
- * \param nb_bits Set the decoding table size (2^nb_bits) entries. The bigger
- * it is, the faster is the decoding. But it should not be too big to save
- * memory and L1 cache. '9' is a good compromise.
- *
- * \param nb_codes Number of vlcs codes.
- *
+ * \param nb_bits Set the decoding table size (2^nb_bits) entries.
+ * \param nb_codes Number of vlc codes.
* \param bits Table which gives the size (in bits) of each vlc code.
- *
* \param codes Table which gives the bit pattern of of each vlc code.
- *
* \param codes_size The number of bytes of each entry of the \a codes tables.
*
+ * The bigger \a nb_bits is, the faster is the decoding. But it should not be
+ * too big to save memory and L1 cache. '9' is a good compromise.
+ *
* The wrap and size parameters allow to use any memory configuration and
* types (byte/word/long) to store the bits and codes tables.
*/
* Parse a vlc code.
*
* \param gbc The getbit context structure.
- *
* \param table The vlc tables to use.
- *
- * \param bits The number of bits which will be read at once, must be
- * identical to nb_bits in init_vlc().
- *
- * \param max_depth The number of times bits bits must be read to completely
+ * \param bits The number of bits which will be read at once.
+ * \param max_depth The number of times \a bits bits must be read to completely
* read the longest vlc code = (max_vlc_length + bits - 1) / bits.
*
+ * The \a bits parameter must be identical to the \a nb_bits value supplied to
+ * \ref init_vlc().
+ *
* \return The vlc code.
*/
int get_vlc(struct getbit_context *gbc, VLC_TYPE(*table)[2], int bits,
/**
* Initialize a getbit_context structure.
*
- * \param buffer The bitstream buffer. It must be 4 bytes larger then the
- * actual read bits because the bitstream reader might read 32 bits at once and
- * could read over the end.
+ * \param gbc The structure to initialize.
+ * \param buffer The bitstream buffer.
+ * \param size The size of the buffer in bytes.
*
- * \param bit_size The size of the buffer in bytes.
+ * The bitstream buffer must be 4 bytes larger then the actual read bits
+ * because the bitstream reader might read 32 bits at once and could read over
+ * the end.
*/
static inline void init_get_bits(struct getbit_context *gbc,
const uint8_t *buffer, int size)
void free_vlc(struct vlc *vlc);
int get_vlc(struct getbit_context *gbc, VLC_TYPE(*table)[2], int bits,
int max_depth);
-
uint32_t bit_rate;
/** Further decoding information (ignored). */
uint32_t flags1;
- /** Whether to use exp_vlc, bit reservoir, variable block len. */
+ /** Encodes exp_vlc, bit reservoir, vbl, number of block sizes. */
uint16_t flags2;
+ /** Whether exponents are coded with VLC codes. */
+ bool use_exp_vlc;
+ /** If false, a frame is equal to a superframe. */
+ bool use_bit_reservoir;
+ /** Whether blocks are of variable or of constant size. */
+ bool use_variable_block_len;
};
/* wma_common.c */
afhi->frequency = ahi.sample_rate;
afhi->channels = ahi.channels;
afhi->header_len = ahi.header_len;
+
+ afhi->techinfo = make_message("%s%s%s%s%s",
+ ahi.use_exp_vlc? "exp vlc" : "",
+ (ahi.use_bit_reservoir && ahi.use_exp_vlc)? ", " : "",
+ ahi.use_bit_reservoir? "bit reservoir" : "",
+ (ahi.use_variable_block_len &&
+ (ahi.use_exp_vlc || ahi.use_bit_reservoir)? ", " : ""),
+ ahi.use_variable_block_len? "vbl" : ""
+ );
wma_make_chunk_table(map + ahi.header_len, numbytes - ahi.header_len,
ahi.block_align, afhi);
read_asf_tags(map, ahi.header_len, &afhi->tags);
ahi->flags2 = read_u16(start + 60);
PARA_INFO_LOG("read_asf_header: flags1: %d, flag2: %d\n",
ahi->flags1, ahi->flags2);
+ ahi->use_exp_vlc = ahi->flags2 & 0x0001;
+ ahi->use_bit_reservoir = ahi->flags2 & 0x0002;
+ ahi->use_variable_block_len = ahi->flags2 & 0x0004;
return 1;
}
/** Information contained in the audio file header. */
struct asf_header_info ahi;
struct getbit_context gb;
- /** Whether to use the bit reservoir. */
- int use_bit_reservoir;
- /** Whether to use variable block length. */
- int use_variable_block_len;
- /** Whether to use exponent coding. */
- int use_exp_vlc;
/** Whether perceptual noise is added. */
int use_noise_coding;
/** Depends on number of the bits per second and the frame length. */
int byte_offset_bits;
- /** Only used if use_exp_vlc is true. */
+ /** Only used if ahi->use_exp_vlc is true. */
struct vlc exp_vlc;
uint16_t exponent_bands[BLOCK_NB_SIZES][25];
/** The index of the first coef in high band. */
int frame_len;
/** log2 of frame_len. */
int frame_len_bits;
- /** Number of block sizes. */
+ /** Number of block sizes, one if !ahi->use_variable_block_len. */
int nb_block_sizes;
/* block info */
int reset_block_lengths;
for (i = 0; i < pwd->nb_block_sizes; i++)
imdct_end(pwd->mdct_ctx[i]);
- if (pwd->use_exp_vlc)
+ if (pwd->ahi.use_exp_vlc)
free_vlc(&pwd->exp_vlc);
if (pwd->use_noise_coding)
free_vlc(&pwd->hgain_vlc);
else
pwd->frame_len_bits = 11;
pwd->frame_len = 1 << pwd->frame_len_bits;
- if (pwd->use_variable_block_len) {
+ if (pwd->ahi.use_variable_block_len) {
int nb_max, nb;
nb = ((flags2 >> 3) & 3) + 1;
if ((ahi->bit_rate / ahi->channels) >= 32000)
pwd->frame_len, bps, bps1,
high_freq, pwd->byte_offset_bits);
PARA_INFO_LOG("use_noise_coding=%d use_exp_vlc=%d nb_block_sizes=%d\n",
- pwd->use_noise_coding, pwd->use_exp_vlc, pwd->nb_block_sizes);
+ pwd->use_noise_coding, pwd->ahi.use_exp_vlc, pwd->nb_block_sizes);
compute_scale_factor_band_sizes(pwd, high_freq);
/* init MDCT windows : simple sinus window */
if (pwd->use_noise_coding) {
/* init the noise generator */
- if (pwd->use_exp_vlc)
+ if (pwd->ahi.use_exp_vlc)
pwd->noise_mult = 0.02;
else
pwd->noise_mult = 0.04;
return ret;
}
- pwd->use_exp_vlc = pwd->ahi.flags2 & 0x0001;
- pwd->use_bit_reservoir = pwd->ahi.flags2 & 0x0002;
- pwd->use_variable_block_len = pwd->ahi.flags2 & 0x0004;
-
ret = wma_init(pwd);
if (ret < 0)
return ret;
wma_hgain_huffcodes, 2);
}
- if (pwd->use_exp_vlc) {
+ if (pwd->ahi.use_exp_vlc) {
PARA_INFO_LOG("using exp_vlc\n");
init_vlc(&pwd->exp_vlc, EXPVLCBITS, sizeof(wma_scale_huffbits),
wma_scale_huffbits, wma_scale_huffcodes, 4);
int nb_coefs[MAX_CHANNELS];
/* compute current block length */
- if (pwd->use_variable_block_len) {
+ if (pwd->ahi.use_variable_block_len) {
n = wma_log2(pwd->nb_block_sizes - 1) + 1;
if (pwd->reset_block_lengths) {
if ((pwd->block_len_bits == pwd->frame_len_bits) || get_bit(&pwd->gb)) {
for (ch = 0; ch < pwd->ahi.channels; ch++) {
if (pwd->channel_coded[ch]) {
- if (pwd->use_exp_vlc) {
+ if (pwd->ahi.use_exp_vlc) {
ret = decode_exp_vlc(pwd, ch);
if (ret < 0)
return ret;
buf_size = pwd->ahi.block_align;
samples = data;
init_get_bits(&pwd->gb, buf, buf_size);
- if (pwd->use_bit_reservoir) {
+ if (pwd->ahi.use_bit_reservoir) {
int i, nb_frames, bit_offset, pos, len;
uint8_t *q;
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