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alsdec.c File Reference

MPEG-4 ALS decoder. More...

#include <inttypes.h>
#include "avcodec.h"
#include "get_bits.h"
#include "unary.h"
#include "mpeg4audio.h"
#include "bytestream.h"
#include "bgmc.h"
#include "bswapdsp.h"
#include "internal.h"
#include "mlz.h"
#include "libavutil/samplefmt.h"
#include "libavutil/crc.h"
#include "libavutil/softfloat_ieee754.h"
#include "libavutil/intfloat.h"
#include "libavutil/intreadwrite.h"
#include <stdint.h>

Go to the source code of this file.

Data Structures

struct  ALSSpecificConfig
 
struct  ALSChannelData
 
struct  ALSDecContext
 
struct  ALSBlockData
 

Macros

#define MISSING_ERR(cond, str, errval)
 
#define INTERLEAVE_OUTPUT(bps)
 

Enumerations

enum  RA_Flag { RA_FLAG_NONE, RA_FLAG_FRAMES, RA_FLAG_HEADER }
 

Functions

static av_cold void dprint_specific_config (ALSDecContext *ctx)
 
static av_cold int read_specific_config (ALSDecContext *ctx)
 Read an ALSSpecificConfig from a buffer into the output struct. More...
 
static int check_specific_config (ALSDecContext *ctx)
 Check the ALSSpecificConfig for unsupported features. More...
 
static void parse_bs_info (const uint32_t bs_info, unsigned int n, unsigned int div, unsigned int **div_blocks, unsigned int *num_blocks)
 Parse the bs_info field to extract the block partitioning used in block switching mode, refer to ISO/IEC 14496-3, section 11.6.2. More...
 
static int32_t decode_rice (GetBitContext *gb, unsigned int k)
 Read and decode a Rice codeword. More...
 
static void parcor_to_lpc (unsigned int k, const int32_t *par, int32_t *cof)
 Convert PARCOR coefficient k to direct filter coefficient. More...
 
static void get_block_sizes (ALSDecContext *ctx, unsigned int *div_blocks, uint32_t *bs_info)
 Read block switching field if necessary and set actual block sizes. More...
 
static int read_const_block_data (ALSDecContext *ctx, ALSBlockData *bd)
 Read the block data for a constant block. More...
 
static void decode_const_block_data (ALSDecContext *ctx, ALSBlockData *bd)
 Decode the block data for a constant block. More...
 
static int read_var_block_data (ALSDecContext *ctx, ALSBlockData *bd)
 Read the block data for a non-constant block. More...
 
static int decode_var_block_data (ALSDecContext *ctx, ALSBlockData *bd)
 Decode the block data for a non-constant block. More...
 
static int read_block (ALSDecContext *ctx, ALSBlockData *bd)
 Read the block data. More...
 
static int decode_block (ALSDecContext *ctx, ALSBlockData *bd)
 Decode the block data. More...
 
static int read_decode_block (ALSDecContext *ctx, ALSBlockData *bd)
 Read and decode block data successively. More...
 
static void zero_remaining (unsigned int b, unsigned int b_max, const unsigned int *div_blocks, int32_t *buf)
 Compute the number of samples left to decode for the current frame and sets these samples to zero. More...
 
static int decode_blocks_ind (ALSDecContext *ctx, unsigned int ra_frame, unsigned int c, const unsigned int *div_blocks, unsigned int *js_blocks)
 Decode blocks independently. More...
 
static int decode_blocks (ALSDecContext *ctx, unsigned int ra_frame, unsigned int c, const unsigned int *div_blocks, unsigned int *js_blocks)
 Decode blocks dependently. More...
 
static int als_weighting (GetBitContext *gb, int k, int off)
 
static int read_channel_data (ALSDecContext *ctx, ALSChannelData *cd, int c)
 Read the channel data. More...
 
static int revert_channel_correlation (ALSDecContext *ctx, ALSBlockData *bd, ALSChannelData **cd, int *reverted, unsigned int offset, int c)
 Recursively reverts the inter-channel correlation for a block. More...
 
static SoftFloat_IEEE754 multiply (SoftFloat_IEEE754 a, SoftFloat_IEEE754 b)
 multiply two softfloats and handle the rounding off More...
 
static int read_diff_float_data (ALSDecContext *ctx, unsigned int ra_frame)
 Read and decode the floating point sample data. More...
 
static int read_frame_data (ALSDecContext *ctx, unsigned int ra_frame)
 Read the frame data. More...
 
static int decode_frame (AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
 Decode an ALS frame. More...
 
static av_cold int decode_end (AVCodecContext *avctx)
 Uninitialize the ALS decoder. More...
 
static av_cold int decode_init (AVCodecContext *avctx)
 Initialize the ALS decoder. More...
 
static av_cold void flush (AVCodecContext *avctx)
 Flush (reset) the frame ID after seeking. More...
 

Variables

static const int8_t parcor_rice_table [3][20][2]
 Rice parameters and corresponding index offsets for decoding the indices of scaled PARCOR values. More...
 
static const int16_t parcor_scaled_values []
 Scaled PARCOR values used for the first two PARCOR coefficients. More...
 
static const uint8_t ltp_gain_values [4][4]
 Gain values of p(0) for long-term prediction. More...
 
static const int16_t mcc_weightings []
 Inter-channel weighting factors for multi-channel correlation. More...
 
static const uint8_t tail_code [16][6]
 Tail codes used in arithmetic coding using block Gilbert-Moore codes. More...
 
AVCodec ff_als_decoder
 

Detailed Description

MPEG-4 ALS decoder.

Author
Thilo Borgmann <thilo.borgmann at mail.de>

Definition in file alsdec.c.

Macro Definition Documentation

#define MISSING_ERR (   cond,
  str,
  errval 
)
Value:
{ \
if (cond) { \
str); \
error = errval; \
} \
}
static void error(const char *err)
AVFormatContext * ctx
Definition: movenc.c:48
void avpriv_report_missing_feature(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
if(ret< 0)
Definition: vf_mcdeint.c:282

Referenced by check_specific_config().

#define INTERLEAVE_OUTPUT (   bps)
Value:
{ \
int##bps##_t *dest = (int##bps##_t*)frame->data[0]; \
shift = bps - ctx->avctx->bits_per_raw_sample; \
if (!ctx->cs_switch) { \
for (sample = 0; sample < ctx->cur_frame_length; sample++) \
for (c = 0; c < avctx->channels; c++) \
*dest++ = ctx->raw_samples[c][sample] << shift; \
} else { \
for (sample = 0; sample < ctx->cur_frame_length; sample++) \
for (c = 0; c < avctx->channels; c++) \
*dest++ = ctx->raw_samples[sconf->chan_pos[c]][sample] << shift; \
} \
}
static int shift(int a, int b)
Definition: sonic.c:82
#define sample
static AVFrame * frame
AVFormatContext * ctx
Definition: movenc.c:48
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:198
int
if(ret< 0)
Definition: vf_mcdeint.c:282
unsigned bps
Definition: movenc.c:1413
static AVCodec * c
for(j=16;j >0;--j)

Referenced by decode_frame().

Enumeration Type Documentation

enum RA_Flag
Enumerator
RA_FLAG_NONE 
RA_FLAG_FRAMES 
RA_FLAG_HEADER 

Definition at line 152 of file alsdec.c.

Function Documentation

static av_cold void dprint_specific_config ( ALSDecContext ctx)
static

Definition at line 262 of file alsdec.c.

Referenced by read_specific_config().

static av_cold int read_specific_config ( ALSDecContext ctx)
static

Read an ALSSpecificConfig from a buffer into the output struct.

Definition at line 292 of file alsdec.c.

Referenced by decode_init().

static int check_specific_config ( ALSDecContext ctx)
static

Check the ALSSpecificConfig for unsupported features.

Definition at line 441 of file alsdec.c.

Referenced by decode_init().

static void parse_bs_info ( const uint32_t  bs_info,
unsigned int  n,
unsigned int  div,
unsigned int **  div_blocks,
unsigned int num_blocks 
)
static

Parse the bs_info field to extract the block partitioning used in block switching mode, refer to ISO/IEC 14496-3, section 11.6.2.

Definition at line 465 of file alsdec.c.

Referenced by get_block_sizes().

static int32_t decode_rice ( GetBitContext gb,
unsigned int  k 
)
static

Read and decode a Rice codeword.

Definition at line 488 of file alsdec.c.

Referenced by als_weighting(), and read_var_block_data().

static void parcor_to_lpc ( unsigned int  k,
const int32_t par,
int32_t cof 
)
static

Convert PARCOR coefficient k to direct filter coefficient.

Definition at line 506 of file alsdec.c.

Referenced by decode_var_block_data().

static void get_block_sizes ( ALSDecContext ctx,
unsigned int div_blocks,
uint32_t *  bs_info 
)
static

Read block switching field if necessary and set actual block sizes.

Also assure that the block sizes of the last frame correspond to the actual number of samples.

Definition at line 526 of file alsdec.c.

Referenced by read_frame_data().

static int read_const_block_data ( ALSDecContext ctx,
ALSBlockData bd 
)
static

Read the block data for a constant block.

Definition at line 579 of file alsdec.c.

Referenced by read_block().

static void decode_const_block_data ( ALSDecContext ctx,
ALSBlockData bd 
)
static

Decode the block data for a constant block.

Definition at line 609 of file alsdec.c.

Referenced by decode_block().

static int read_var_block_data ( ALSDecContext ctx,
ALSBlockData bd 
)
static

Read the block data for a non-constant block.

Definition at line 623 of file alsdec.c.

Referenced by read_block().

static int decode_var_block_data ( ALSDecContext ctx,
ALSBlockData bd 
)
static

Decode the block data for a non-constant block.

Definition at line 892 of file alsdec.c.

Referenced by decode_block().

static int read_block ( ALSDecContext ctx,
ALSBlockData bd 
)
static

Read the block data.

Definition at line 1001 of file alsdec.c.

Referenced by read_decode_block(), and read_frame_data().

static int decode_block ( ALSDecContext ctx,
ALSBlockData bd 
)
static

Decode the block data.

Definition at line 1024 of file alsdec.c.

Referenced by read_decode_block(), and read_frame_data().

static int read_decode_block ( ALSDecContext ctx,
ALSBlockData bd 
)
static

Read and decode block data successively.

Definition at line 1050 of file alsdec.c.

Referenced by decode_blocks(), and decode_blocks_ind().

static void zero_remaining ( unsigned int  b,
unsigned int  b_max,
const unsigned int div_blocks,
int32_t buf 
)
static

Compute the number of samples left to decode for the current frame and sets these samples to zero.

Definition at line 1064 of file alsdec.c.

Referenced by decode_blocks(), and decode_blocks_ind().

static int decode_blocks_ind ( ALSDecContext ctx,
unsigned int  ra_frame,
unsigned int  c,
const unsigned int div_blocks,
unsigned int js_blocks 
)
static

Decode blocks independently.

Definition at line 1079 of file alsdec.c.

Referenced by read_frame_data().

static int decode_blocks ( ALSDecContext ctx,
unsigned int  ra_frame,
unsigned int  c,
const unsigned int div_blocks,
unsigned int js_blocks 
)
static

Decode blocks dependently.

Definition at line 1119 of file alsdec.c.

Referenced by read_frame_data().

static int als_weighting ( GetBitContext gb,
int  k,
int  off 
)
inlinestatic

Definition at line 1203 of file alsdec.c.

Referenced by read_channel_data().

static int read_channel_data ( ALSDecContext ctx,
ALSChannelData cd,
int  c 
)
static

Read the channel data.

Definition at line 1212 of file alsdec.c.

Referenced by read_frame_data().

static int revert_channel_correlation ( ALSDecContext ctx,
ALSBlockData bd,
ALSChannelData **  cd,
int reverted,
unsigned int  offset,
int  c 
)
static

Recursively reverts the inter-channel correlation for a block.

Definition at line 1259 of file alsdec.c.

Referenced by read_frame_data().

static SoftFloat_IEEE754 multiply ( SoftFloat_IEEE754  a,
SoftFloat_IEEE754  b 
)
static

multiply two softfloats and handle the rounding off

Definition at line 1372 of file alsdec.c.

Referenced by checkasm_check_blend(), and read_diff_float_data().

static int read_diff_float_data ( ALSDecContext ctx,
unsigned int  ra_frame 
)
static

Read and decode the floating point sample data.

Definition at line 1424 of file alsdec.c.

Referenced by read_frame_data().

static int read_frame_data ( ALSDecContext ctx,
unsigned int  ra_frame 
)
static

Read the frame data.

< block sizes.

Definition at line 1604 of file alsdec.c.

Referenced by decode_frame().

static int decode_frame ( AVCodecContext avctx,
void data,
int got_frame_ptr,
AVPacket avpkt 
)
static

Decode an ALS frame.

Definition at line 1758 of file alsdec.c.

static av_cold int decode_end ( AVCodecContext avctx)
static

Uninitialize the ALS decoder.

Definition at line 1887 of file alsdec.c.

Referenced by decode_init().

static av_cold int decode_init ( AVCodecContext avctx)
static

Initialize the ALS decoder.

Definition at line 1939 of file alsdec.c.

static av_cold void flush ( AVCodecContext avctx)
static

Flush (reset) the frame ID after seeking.

Definition at line 2132 of file alsdec.c.

Variable Documentation

const int8_t parcor_rice_table[3][20][2]
static
Initial value:
= {
{ {-52, 4}, {-29, 5}, {-31, 4}, { 19, 4}, {-16, 4},
{ 12, 3}, { -7, 3}, { 9, 3}, { -5, 3}, { 6, 3},
{ -4, 3}, { 3, 3}, { -3, 2}, { 3, 2}, { -2, 2},
{ 3, 2}, { -1, 2}, { 2, 2}, { -1, 2}, { 2, 2} },
{ {-58, 3}, {-42, 4}, {-46, 4}, { 37, 5}, {-36, 4},
{ 29, 4}, {-29, 4}, { 25, 4}, {-23, 4}, { 20, 4},
{-17, 4}, { 16, 4}, {-12, 4}, { 12, 3}, {-10, 4},
{ 7, 3}, { -4, 4}, { 3, 3}, { -1, 3}, { 1, 3} },
{ {-59, 3}, {-45, 5}, {-50, 4}, { 38, 4}, {-39, 4},
{ 32, 4}, {-30, 4}, { 25, 3}, {-23, 3}, { 20, 3},
{-20, 3}, { 16, 3}, {-13, 3}, { 10, 3}, { -7, 3},
{ 3, 3}, { 0, 3}, { -1, 3}, { 2, 3}, { -1, 2} }
}

Rice parameters and corresponding index offsets for decoding the indices of scaled PARCOR values.

The table chosen is set globally by the encoder and stored in ALSSpecificConfig.

Definition at line 51 of file alsdec.c.

Referenced by read_var_block_data().

const int16_t parcor_scaled_values[]
static

Scaled PARCOR values used for the first two PARCOR coefficients.

To be indexed by the Rice coded indices. Generated by: parcor_scaled_values[i] = 32 + ((i * (i+1)) << 7) - (1 << 20) Actual values are divided by 32 in order to be stored in 16 bits.

Definition at line 72 of file alsdec.c.

Referenced by read_var_block_data().

const uint8_t ltp_gain_values[4][4]
static
Initial value:
= {
{ 0, 8, 16, 24},
{32, 40, 48, 56},
{64, 70, 76, 82},
{88, 92, 96, 100}
}

Gain values of p(0) for long-term prediction.

To be indexed by the Rice coded indices.

Definition at line 111 of file alsdec.c.

Referenced by read_var_block_data().

const int16_t mcc_weightings[]
static
Initial value:
= {
204, 192, 179, 166, 153, 140, 128, 115,
102, 89, 76, 64, 51, 38, 25, 12,
0, -12, -25, -38, -51, -64, -76, -89,
-102, -115, -128, -140, -153, -166, -179, -192
}

Inter-channel weighting factors for multi-channel correlation.

To be indexed by the Rice coded indices.

Definition at line 122 of file alsdec.c.

Referenced by als_weighting().

const uint8_t tail_code[16][6]
static
Initial value:
= {
{ 74, 44, 25, 13, 7, 3},
{ 68, 42, 24, 13, 7, 3},
{ 58, 39, 23, 13, 7, 3},
{126, 70, 37, 19, 10, 5},
{132, 70, 37, 20, 10, 5},
{124, 70, 38, 20, 10, 5},
{120, 69, 37, 20, 11, 5},
{116, 67, 37, 20, 11, 5},
{108, 66, 36, 20, 10, 5},
{102, 62, 36, 20, 10, 5},
{ 88, 58, 34, 19, 10, 5},
{162, 89, 49, 25, 13, 7},
{156, 87, 49, 26, 14, 7},
{150, 86, 47, 26, 14, 7},
{142, 84, 47, 26, 14, 7},
{131, 79, 46, 26, 14, 7}
}

Tail codes used in arithmetic coding using block Gilbert-Moore codes.

Definition at line 132 of file alsdec.c.

Referenced by read_var_block_data().

AVCodec ff_als_decoder
Initial value:
= {
.name = "als",
.long_name = NULL_IF_CONFIG_SMALL("MPEG-4 Audio Lossless Coding (ALS)"),
.priv_data_size = sizeof(ALSDecContext),
.close = decode_end,
}
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
static av_cold int decode_init(AVCodecContext *avctx)
Initialize the ALS decoder.
Definition: alsdec.c:1939
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
static av_cold int decode_end(AVCodecContext *avctx)
Uninitialize the ALS decoder.
Definition: alsdec.c:1887
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Decode an ALS frame.
Definition: alsdec.c:1758
#define AV_CODEC_CAP_SUBFRAMES
Codec can output multiple frames per AVPacket Normally demuxers return one frame at a time...
Definition: avcodec.h:1009
static av_cold void flush(AVCodecContext *avctx)
Flush (reset) the frame ID after seeking.
Definition: alsdec.c:2132
static int decode(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *pkt)
Definition: ffmpeg.c:2045
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:959

Definition at line 2140 of file alsdec.c.