mirror of https://git.ffmpeg.org/ffmpeg.git
af_hdcd: Code comments update
Signed-off-by: Burt P <pburt0@gmail.com>
This commit is contained in:
Burt P
parent
45e5d5f547
commit
400e2acd11
|
|
@ -1,40 +1,46 @@
|
|||
/*
|
||||
Copyright (C) 2010, Chris Moeller,
|
||||
All rights reserved.
|
||||
Optimizations by Gumboot
|
||||
Redistribution and use in source and binary forms, with or without modification,
|
||||
are permitted provided that the following conditions are met:
|
||||
1. Redistributions of source code must retain the above copyright
|
||||
notice, this list of conditions and the following disclaimer.
|
||||
2. 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.
|
||||
3. The names of its contributors may not 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.
|
||||
* Copyright (C) 2010, Chris Moeller,
|
||||
* All rights reserved.
|
||||
* Optimizations by Gumboot
|
||||
* Additional work by Burt P.
|
||||
* Original code reverse engineered from HDCD decoder library by Christopher Key,
|
||||
* which was likely reverse engineered from Windows Media Player.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without modification,
|
||||
* are permitted provided that the following conditions are met:
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. 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.
|
||||
* 3. The names of its contributors may not 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.
|
||||
*/
|
||||
|
||||
/*
|
||||
Original code reverse engineered from HDCD decoder library by Christopher Key,
|
||||
which was likely reverse engineered from Windows Media Player.
|
||||
* HDCD is High Definition Compatible Digital
|
||||
* http://wiki.hydrogenaud.io/index.php?title=High_Definition_Compatible_Digital
|
||||
*
|
||||
* More information about HDCD-encoded audio CDs:
|
||||
* http://www.audiomisc.co.uk/HFN/HDCD/Enigma.html
|
||||
* http://www.audiomisc.co.uk/HFN/HDCD/Examined.html
|
||||
*/
|
||||
|
||||
/*
|
||||
HDCD is High Definition Compatible Digital
|
||||
More information about HDCD-encoded audio CDs:
|
||||
http://www.audiomisc.co.uk/HFN/HDCD/Enigma.html
|
||||
http://www.audiomisc.co.uk/HFN/HDCD/Examined.html
|
||||
/**
|
||||
* @file
|
||||
* HDCD decoding filter
|
||||
*/
|
||||
|
||||
#include "libavutil/opt.h"
|
||||
|
|
@ -820,34 +826,34 @@ typedef struct {
|
|||
uint64_t window;
|
||||
unsigned char readahead;
|
||||
|
||||
/* arg is set when a packet prefix is found.
|
||||
* control is the active control code, where
|
||||
* bit 0-3: target_gain, 4-bit (3.1) fixed-point value
|
||||
* bit 4 : peak_extend
|
||||
* bit 5 : transient_filter
|
||||
* bit 6,7: always zero */
|
||||
unsigned char arg, control;
|
||||
unsigned sustain, sustain_reset; /* code detect timer */
|
||||
/** arg is set when a packet prefix is found.
|
||||
* control is the active control code, where
|
||||
* bit 0-3: target_gain, 4-bit (3.1) fixed-point value
|
||||
* bit 4 : peak_extend
|
||||
* bit 5 : transient_filter
|
||||
* bit 6,7: always zero */
|
||||
uint8_t arg, control;
|
||||
unsigned int sustain, sustain_reset; /**< code detect timer */
|
||||
|
||||
int running_gain; /* 11-bit (3.8) fixed point, extended from target_gain */
|
||||
int running_gain; /**< 11-bit (3.8) fixed point, extended from target_gain */
|
||||
|
||||
/* counters */
|
||||
int code_counterA; /* 8-bit format packet */
|
||||
int code_counterA_almost; /* looks like an A code, but a bit expected to be 0 is 1 */
|
||||
int code_counterB; /* 16-bit format packet, 8-bit code, 8-bit XOR of code */
|
||||
int code_counterB_checkfails; /* looks like a B code, but doesn't pass the XOR check */
|
||||
int code_counterC; /* packet prefix was found, expect a code */
|
||||
int code_counterC_unmatched; /* told to look for a code, but didn't find one */
|
||||
int count_peak_extend; /* valid packets where peak_extend was enabled */
|
||||
int count_transient_filter; /* valid packets where filter was detected */
|
||||
/* target_gain is a 4-bit (3.1) fixed-point value, always
|
||||
* negative, but stored positive.
|
||||
* The 16 possible values range from -7.5 to 0.0 dB in
|
||||
* steps of 0.5, but no value below -6.0 dB should appear. */
|
||||
int gain_counts[16]; /* for cursiosity, mostly */
|
||||
int code_counterA; /**< 8-bit format packet */
|
||||
int code_counterA_almost; /**< looks like an A code, but a bit expected to be 0 is 1 */
|
||||
int code_counterB; /**< 16-bit format packet, 8-bit code, 8-bit XOR of code */
|
||||
int code_counterB_checkfails; /**< looks like a B code, but doesn't pass the XOR check */
|
||||
int code_counterC; /**< packet prefix was found, expect a code */
|
||||
int code_counterC_unmatched; /**< told to look for a code, but didn't find one */
|
||||
int count_peak_extend; /**< valid packets where peak_extend was enabled */
|
||||
int count_transient_filter; /**< valid packets where filter was detected */
|
||||
/** target_gain is a 4-bit (3.1) fixed-point value, always
|
||||
* negative, but stored positive.
|
||||
* The 16 possible values range from -7.5 to 0.0 dB in
|
||||
* steps of 0.5, but no value below -6.0 dB should appear. */
|
||||
int gain_counts[16];
|
||||
int max_gain;
|
||||
/* occurences of code detect timer expiring without detecting
|
||||
* a code. -1 for timer never set. */
|
||||
/** occurences of code detect timer expiring without detecting
|
||||
* a code. -1 for timer never set. */
|
||||
int count_sustain_expired;
|
||||
} hdcd_state_t;
|
||||
|
||||
|
|
@ -866,8 +872,8 @@ static const char * const pe_str[] = {
|
|||
#define HDCD_PROCESS_STEREO_DEFAULT 1
|
||||
#define HDCD_MAX_CHANNELS 2
|
||||
|
||||
/* convert to float from 4-bit (3.1) fixed-point
|
||||
* the always-negative value is stored positive, so make it negative */
|
||||
/** convert to float from 4-bit (3.1) fixed-point
|
||||
* the always-negative value is stored positive, so make it negative */
|
||||
#define GAINTOFLOAT(g) (g) ? -(float)(g>>1) - ((g & 1) ? 0.5 : 0.0) : 0.0
|
||||
|
||||
#define HDCD_ANA_OFF 0
|
||||
|
|
@ -894,38 +900,40 @@ typedef struct HDCDContext {
|
|||
const AVClass *class;
|
||||
hdcd_state_t state[HDCD_MAX_CHANNELS];
|
||||
|
||||
/* use hdcd_*_stereo() functions to process both channels together.
|
||||
* -af hdcd=process_stereo=0 for off
|
||||
* -af hdcd=process_stereo=1 for on
|
||||
* default is HDCD_PROCESS_STEREO_DEFAULT */
|
||||
/* AVOption members */
|
||||
/** use hdcd_*_stereo() functions to process both channels together.
|
||||
* -af hdcd=process_stereo=0 for off
|
||||
* -af hdcd=process_stereo=1 for on
|
||||
* default is HDCD_PROCESS_STEREO_DEFAULT */
|
||||
int process_stereo;
|
||||
/* always extend peaks above -3dBFS even if PE isn't signaled
|
||||
* -af hdcd=force_pe=0 for off
|
||||
* -af hdcd=force_pe=1 for on
|
||||
* default is off */
|
||||
/** always extend peaks above -3dBFS even if PE isn't signaled
|
||||
* -af hdcd=force_pe=0 for off
|
||||
* -af hdcd=force_pe=1 for on
|
||||
* default is off */
|
||||
int force_pe;
|
||||
|
||||
/* analyze mode replaces the audio with a solid tone and adjusts
|
||||
* the amplitude to signal some specific aspect of the decoding
|
||||
* process. See docs or HDCD_ANA_* defines. */
|
||||
/** analyze mode replaces the audio with a solid tone and adjusts
|
||||
* the amplitude to signal some specific aspect of the decoding
|
||||
* process. See docs or HDCD_ANA_* defines. */
|
||||
int analyze_mode;
|
||||
int ana_snb; /* used in tone generation */
|
||||
int ana_snb; /**< used in tone generation */
|
||||
/* end AVOption members */
|
||||
|
||||
/* config_input() and config_output() scan links for any resampling
|
||||
* or format changes. If found, warnings are issued and bad_config
|
||||
* is set. */
|
||||
/** config_input() and config_output() scan links for any resampling
|
||||
* or format changes. If found, warnings are issued and bad_config
|
||||
* is set. */
|
||||
int bad_config;
|
||||
|
||||
AVFilterContext *fctx; /* filter context for logging errors */
|
||||
int sample_count; /* used in error logging */
|
||||
int val_target_gain; /* last matching target_gain in both channels */
|
||||
AVFilterContext *fctx; /**< filter context for logging errors */
|
||||
int sample_count; /**< used in error logging */
|
||||
int val_target_gain; /**< last matching target_gain in both channels */
|
||||
|
||||
/* User information/stats */
|
||||
int hdcd_detected;
|
||||
int det_errors; /* detectable errors */
|
||||
hdcd_pe_t peak_extend;
|
||||
int uses_transient_filter; /* detected, but not implemented */
|
||||
float max_gain_adjustment; /* in dB, expected in the range -6.0 to 0.0 */
|
||||
int hdcd_detected; /**< Valid HDCD coding was detected */
|
||||
int det_errors; /**< detectable errors */
|
||||
hdcd_pe_t peak_extend; /**< peak exted used */
|
||||
int uses_transient_filter; /**< transient filter flag detected */
|
||||
float max_gain_adjustment; /**< in dB, expected in the range -7.5 to 0.0 */
|
||||
} HDCDContext;
|
||||
|
||||
#define OFFSET(x) offsetof(HDCDContext, x)
|
||||
|
|
@ -976,7 +984,7 @@ static void hdcd_reset(hdcd_state_t *state, unsigned rate)
|
|||
state->count_sustain_expired = -1;
|
||||
}
|
||||
|
||||
/* update the user info/counters */
|
||||
/** update the user info/counters */
|
||||
static void hdcd_update_info(hdcd_state_t *state)
|
||||
{
|
||||
if (state->control & 16) state->count_peak_extend++;
|
||||
|
|
@ -1242,7 +1250,7 @@ static int hdcd_scan_stereo(HDCDContext *ctx, const int32_t *samples, int max)
|
|||
return result;
|
||||
}
|
||||
|
||||
/* encode a value in the given sample by adjusting the amplitude */
|
||||
/** encode a value in the given sample by adjusting the amplitude */
|
||||
static int32_t hdcd_analyze_gen(int32_t sample, unsigned int v, unsigned int maxv)
|
||||
{
|
||||
float sflt = sample, vv = v;
|
||||
|
|
@ -1252,8 +1260,8 @@ static int32_t hdcd_analyze_gen(int32_t sample, unsigned int v, unsigned int max
|
|||
return (int32_t)sflt;
|
||||
}
|
||||
|
||||
/* behaves like hdcd_envelope(), but encodes processing information in
|
||||
* a way that is audible (and visible in an audio editor) to aid analysis. */
|
||||
/** behaves like hdcd_envelope(), but encodes processing information in
|
||||
* a way that is audible (and visible in an audio editor) to aid analysis. */
|
||||
static int hdcd_analyze(int32_t *samples, int count, int stride, int gain, int target_gain, int extend, int mode, int cdt_active, int tg_mismatch)
|
||||
{
|
||||
static const int maxg = 0xf << 7;
|
||||
|
|
@ -1313,6 +1321,7 @@ static int hdcd_analyze(int32_t *samples, int count, int stride, int gain, int t
|
|||
return gain;
|
||||
}
|
||||
|
||||
/** apply HDCD decoding parameters to a series of samples */
|
||||
static int hdcd_envelope(int32_t *samples, int count, int stride, int gain, int target_gain, int extend)
|
||||
{
|
||||
int i;
|
||||
|
|
@ -1372,7 +1381,7 @@ static int hdcd_envelope(int32_t *samples, int count, int stride, int gain, int
|
|||
return gain;
|
||||
}
|
||||
|
||||
/* extract fields from control code */
|
||||
/** extract fields from control code */
|
||||
static void hdcd_control(HDCDContext *ctx, hdcd_state_t *state, int *peak_extend, int *target_gain)
|
||||
{
|
||||
*peak_extend = (ctx->force_pe || state->control & 16);
|
||||
|
|
@ -1500,7 +1509,7 @@ static void hdcd_process_stereo(HDCDContext *ctx, int32_t *samples, int count)
|
|||
ctx->state[1].running_gain = gain[1];
|
||||
}
|
||||
|
||||
/* tone generator: sample_number, frequency, sample_rate, amplitude */
|
||||
/** tone generator: sample_number, frequency, sample_rate, amplitude */
|
||||
#define TONEGEN16(sn, f, sr, a) (int16_t)(sin((6.28318530718 * (sn) * (f)) /(sr)) * (a) * 0x7fff)
|
||||
|
||||
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
|
||||
|
|
|
|||
Loading…
Reference in New Issue