mirror of https://github.com/FFmpeg/FFmpeg.git
parent
62b5197f97
commit
b33fd66f46
6 changed files with 499 additions and 1 deletions
@ -0,0 +1,482 @@ |
||||
/*
|
||||
* Wavesynth pseudo-codec |
||||
* Copyright (c) 2011 Nicolas George |
||||
* |
||||
* This file is part of FFmpeg. |
||||
* |
||||
* FFmpeg 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, |
||||
* 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 |
||||
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
||||
*/ |
||||
|
||||
#include "libavutil/intreadwrite.h" |
||||
#include "libavutil/log.h" |
||||
#include "avcodec.h" |
||||
|
||||
#define SIN_BITS 14 |
||||
#define WS_MAX_CHANNELS 32 |
||||
#define INF_TS 0x7FFFFFFFFFFFFFFF |
||||
|
||||
#define PINK_UNIT 128 |
||||
|
||||
/*
|
||||
Format of the extradata and packets |
||||
|
||||
THIS INFORMATION IS NOT PART OF THE PUBLIC API OR ABI. |
||||
IT CAN CHANGE WITHOUT NOTIFICATION. |
||||
|
||||
All numbers are in little endian. |
||||
|
||||
The codec extradata define a set of intervals with uniform content. |
||||
Overlapping intervals are added together. |
||||
|
||||
extradata: |
||||
uint32 number of intervals |
||||
... intervals |
||||
|
||||
interval: |
||||
int64 start timestamp; time_base must be 1/sample_rate; |
||||
start timestamps must be in ascending order |
||||
int64 end timestamp |
||||
uint32 type |
||||
uint32 channels mask |
||||
... additional information, depends on type |
||||
|
||||
sine interval (type fourcc "SINE"): |
||||
int32 start frequency, in 1/(1<<16) Hz |
||||
int32 end frequency |
||||
int32 start amplitude, 1<<16 is the full amplitude |
||||
int32 end amplitude |
||||
uint32 start phase, 0 is sin(0), 0x20000000 is sin(pi/2), etc.; |
||||
n | (1<<31) means to match the phase of previous channel #n |
||||
|
||||
pink noise interval (type fourcc "NOIS"): |
||||
int32 start amplitude |
||||
int32 end amplitude |
||||
|
||||
The input packets encode the time and duration of the requested segment. |
||||
|
||||
packet: |
||||
int64 start timestamp |
||||
int32 duration |
||||
|
||||
*/ |
||||
|
||||
enum ws_interval_type { |
||||
WS_SINE = MKTAG('S','I','N','E'), |
||||
WS_NOISE = MKTAG('N','O','I','S'), |
||||
}; |
||||
|
||||
struct ws_interval { |
||||
int64_t ts_start, ts_end; |
||||
uint64_t phi0, dphi0, ddphi; |
||||
uint64_t amp0, damp; |
||||
uint64_t phi, dphi, amp; |
||||
uint32_t channels; |
||||
enum ws_interval_type type; |
||||
int next; |
||||
}; |
||||
|
||||
struct wavesynth_context { |
||||
int64_t cur_ts; |
||||
int64_t next_ts; |
||||
int32_t *sin; |
||||
AVFrame frame; |
||||
struct ws_interval *inter; |
||||
uint32_t dither_state; |
||||
uint32_t pink_state; |
||||
int32_t pink_pool[PINK_UNIT]; |
||||
unsigned pink_need, pink_pos; |
||||
int nb_inter; |
||||
int cur_inter; |
||||
int next_inter; |
||||
}; |
||||
|
||||
#define LCG_A 1284865837 |
||||
#define LCG_C 4150755663 |
||||
#define LCG_AI 849225893 /* A*AI = 1 [mod 1<<32] */ |
||||
|
||||
static uint32_t lcg_next(uint32_t *s) |
||||
{ |
||||
*s = *s * LCG_A + LCG_C; |
||||
return *s; |
||||
} |
||||
|
||||
static void lcg_seek(uint32_t *s, int64_t dt) |
||||
{ |
||||
uint32_t a, c, t = *s; |
||||
|
||||
if (dt >= 0) { |
||||
a = LCG_A; |
||||
c = LCG_C; |
||||
} else { /* coefficients for a step backward */ |
||||
a = LCG_AI; |
||||
c = (uint32_t)(LCG_AI * LCG_C); |
||||
dt = -dt; |
||||
} |
||||
while (dt) { |
||||
if (dt & 1) |
||||
t = a * t + c; |
||||
c *= a + 1; /* coefficients for a double step */ |
||||
a *= a; |
||||
dt >>= 1; |
||||
} |
||||
*s = t; |
||||
} |
||||
|
||||
/* Emulate pink noise by summing white noise at the sampling frequency,
|
||||
* white noise at half the sampling frequency (each value taken twice), |
||||
* etc., with a total of 8 octaves. |
||||
* This is known as the Voss-McCartney algorithm. */ |
||||
|
||||
static void pink_fill(struct wavesynth_context *ws) |
||||
{ |
||||
int32_t vt[7] = { 0 }, v = 0; |
||||
int i, j; |
||||
|
||||
ws->pink_pos = 0; |
||||
if (!ws->pink_need) |
||||
return; |
||||
for (i = 0; i < PINK_UNIT; i++) { |
||||
for (j = 0; j < 7; j++) { |
||||
if ((i >> j) & 1) |
||||
break; |
||||
v -= vt[j]; |
||||
vt[j] = (int32_t)lcg_next(&ws->pink_state) >> 3; |
||||
v += vt[j]; |
||||
} |
||||
ws->pink_pool[i] = v + ((int32_t)lcg_next(&ws->pink_state) >> 3); |
||||
} |
||||
lcg_next(&ws->pink_state); /* so we use exactly 256 steps */ |
||||
} |
||||
|
||||
/**
|
||||
* @return (1<<64) * a / b, without overflow, if a < b |
||||
*/ |
||||
static uint64_t frac64(uint64_t a, uint64_t b) |
||||
{ |
||||
uint64_t r = 0; |
||||
int i; |
||||
|
||||
if (b < (uint64_t)1 << 32) { /* b small, use two 32-bits steps */ |
||||
a <<= 32; |
||||
return ((a / b) << 32) | ((a % b) << 32) / b; |
||||
} |
||||
if (b < (uint64_t)1 << 48) { /* b medium, use four 16-bits steps */ |
||||
for (i = 0; i < 4; i++) { |
||||
a <<= 16; |
||||
r = (r << 16) | (a / b); |
||||
a %= b; |
||||
} |
||||
return r; |
||||
} |
||||
for (i = 63; i >= 0; i--) { |
||||
if (a >= (uint64_t)1 << 63 || a << 1 >= b) { |
||||
r |= (uint64_t)1 << i; |
||||
a = (a << 1) - b; |
||||
} else { |
||||
a <<= 1; |
||||
} |
||||
} |
||||
return r; |
||||
} |
||||
|
||||
static uint64_t phi_at(struct ws_interval *in, int64_t ts) |
||||
{ |
||||
uint64_t dt = ts - in->ts_start; |
||||
uint64_t dt2 = dt & 1 ? /* dt * (dt - 1) / 2 without overflow */ |
||||
dt * ((dt - 1) >> 1) : (dt >> 1) * (dt - 1); |
||||
return in->phi0 + dt * in->dphi0 + dt2 * in->ddphi; |
||||
} |
||||
|
||||
static void wavesynth_seek(struct wavesynth_context *ws, int64_t ts) |
||||
{ |
||||
int *last, i; |
||||
struct ws_interval *in; |
||||
|
||||
last = &ws->cur_inter; |
||||
for (i = 0; i < ws->nb_inter; i++) { |
||||
in = &ws->inter[i]; |
||||
if (ts < in->ts_start) |
||||
break; |
||||
if (ts >= in->ts_end) |
||||
continue; |
||||
*last = i; |
||||
last = &in->next; |
||||
in->phi = phi_at(in, ts); |
||||
in->dphi = in->dphi0 + (ts - in->ts_start) * in->ddphi; |
||||
in->amp = in->amp0 + (ts - in->ts_start) * in->damp; |
||||
} |
||||
ws->next_inter = i; |
||||
ws->next_ts = i < ws->nb_inter ? ws->inter[i].ts_start : INF_TS; |
||||
*last = -1; |
||||
lcg_seek(&ws->dither_state, ts - ws->cur_ts); |
||||
if (ws->pink_need) { |
||||
int64_t pink_ts_cur = (ws->cur_ts + PINK_UNIT - 1) & ~(PINK_UNIT - 1); |
||||
int64_t pink_ts_next = ts & ~(PINK_UNIT - 1); |
||||
int pos = ts & (PINK_UNIT - 1); |
||||
lcg_seek(&ws->pink_state, (pink_ts_next - pink_ts_cur) << 1); |
||||
if (pos) { |
||||
pink_fill(ws); |
||||
ws->pink_pos = pos; |
||||
} else { |
||||
ws->pink_pos = PINK_UNIT; |
||||
} |
||||
} |
||||
ws->cur_ts = ts; |
||||
} |
||||
|
||||
static int wavesynth_parse_extradata(AVCodecContext *avc) |
||||
{ |
||||
struct wavesynth_context *ws = avc->priv_data; |
||||
struct ws_interval *in; |
||||
uint8_t *edata, *edata_end; |
||||
int32_t f1, f2, a1, a2; |
||||
uint32_t phi; |
||||
int64_t dphi1, dphi2, dt, cur_ts = -0x8000000000000000; |
||||
int i; |
||||
|
||||
if (avc->extradata_size < 4) |
||||
return AVERROR(EINVAL); |
||||
edata = avc->extradata; |
||||
edata_end = edata + avc->extradata_size; |
||||
ws->nb_inter = AV_RL32(edata); |
||||
edata += 4; |
||||
if (ws->nb_inter < 0) |
||||
return AVERROR(EINVAL); |
||||
ws->inter = av_calloc(ws->nb_inter, sizeof(*ws->inter)); |
||||
if (!ws->inter) |
||||
return AVERROR(ENOMEM); |
||||
for (i = 0; i < ws->nb_inter; i++) { |
||||
in = &ws->inter[i]; |
||||
if (edata_end - edata < 24) |
||||
return AVERROR(EINVAL); |
||||
in->ts_start = AV_RL64(edata + 0); |
||||
in->ts_end = AV_RL64(edata + 8); |
||||
in->type = AV_RL32(edata + 16); |
||||
in->channels = AV_RL32(edata + 20); |
||||
edata += 24; |
||||
if (in->ts_start < cur_ts || in->ts_end <= in->ts_start) |
||||
return AVERROR(EINVAL); |
||||
cur_ts = in->ts_start; |
||||
dt = in->ts_end - in->ts_start; |
||||
switch (in->type) { |
||||
case WS_SINE: |
||||
if (edata_end - edata < 20) |
||||
return AVERROR(EINVAL); |
||||
f1 = AV_RL32(edata + 0); |
||||
f2 = AV_RL32(edata + 4); |
||||
a1 = AV_RL32(edata + 8); |
||||
a2 = AV_RL32(edata + 12); |
||||
phi = AV_RL32(edata + 16); |
||||
edata += 20; |
||||
dphi1 = frac64(f1, (int64_t)avc->sample_rate << 16); |
||||
dphi2 = frac64(f2, (int64_t)avc->sample_rate << 16); |
||||
in->dphi0 = dphi1; |
||||
in->ddphi = (dphi2 - dphi1) / dt; |
||||
if (phi & 0x80000000) { |
||||
phi &= ~0x80000000; |
||||
if (phi >= i) |
||||
return AVERROR(EINVAL); |
||||
in->phi0 = phi_at(&ws->inter[phi], in->ts_start); |
||||
} else { |
||||
in->phi0 = (uint64_t)phi << 33; |
||||
} |
||||
break; |
||||
case WS_NOISE: |
||||
if (edata_end - edata < 8) |
||||
return AVERROR(EINVAL); |
||||
a1 = AV_RL32(edata + 0); |
||||
a2 = AV_RL32(edata + 4); |
||||
edata += 8; |
||||
break; |
||||
default: |
||||
return AVERROR(EINVAL); |
||||
} |
||||
in->amp0 = (int64_t)a1 << 32; |
||||
in->damp = (((int64_t)a2 << 32) - ((int64_t)a1 << 32)) / dt; |
||||
} |
||||
if (edata != edata_end) |
||||
return AVERROR(EINVAL); |
||||
return 0; |
||||
} |
||||
|
||||
static av_cold int wavesynth_init(AVCodecContext *avc) |
||||
{ |
||||
struct wavesynth_context *ws = avc->priv_data; |
||||
int i, r; |
||||
|
||||
if (avc->channels > WS_MAX_CHANNELS) { |
||||
av_log(avc, AV_LOG_ERROR, |
||||
"This implementation is limited to %d channels.\n", |
||||
WS_MAX_CHANNELS); |
||||
return AVERROR(EINVAL); |
||||
} |
||||
r = wavesynth_parse_extradata(avc); |
||||
if (r < 0) { |
||||
av_log(avc, AV_LOG_ERROR, "Invalid intervals definitions.\n"); |
||||
goto fail; |
||||
} |
||||
ws->sin = av_malloc(sizeof(*ws->sin) << SIN_BITS); |
||||
if (!ws->sin) { |
||||
r = AVERROR(ENOMEM); |
||||
goto fail; |
||||
} |
||||
for (i = 0; i < 1 << SIN_BITS; i++) |
||||
ws->sin[i] = floor(32767 * sin(2 * M_PI * i / (1 << SIN_BITS))); |
||||
ws->dither_state = MKTAG('D','I','T','H'); |
||||
for (i = 0; i < ws->nb_inter; i++) |
||||
ws->pink_need += ws->inter[i].type == WS_NOISE; |
||||
ws->pink_state = MKTAG('P','I','N','K'); |
||||
ws->pink_pos = PINK_UNIT; |
||||
avcodec_get_frame_defaults(&ws->frame); |
||||
avc->coded_frame = &ws->frame; |
||||
wavesynth_seek(ws, 0); |
||||
avc->sample_fmt = AV_SAMPLE_FMT_S16; |
||||
return 0; |
||||
|
||||
fail: |
||||
av_free(ws->inter); |
||||
av_free(ws->sin); |
||||
return r; |
||||
} |
||||
|
||||
static void wavesynth_synth_sample(struct wavesynth_context *ws, int64_t ts, |
||||
int32_t *channels) |
||||
{ |
||||
int32_t amp, val, *cv; |
||||
struct ws_interval *in; |
||||
int i, *last, pink; |
||||
uint32_t c, all_ch = 0; |
||||
|
||||
i = ws->cur_inter; |
||||
last = &ws->cur_inter; |
||||
if (ws->pink_pos == PINK_UNIT) |
||||
pink_fill(ws); |
||||
pink = ws->pink_pool[ws->pink_pos++] >> 16; |
||||
while (i >= 0) { |
||||
in = &ws->inter[i]; |
||||
i = in->next; |
||||
if (ts >= in->ts_end) { |
||||
*last = i; |
||||
continue; |
||||
} |
||||
last = &in->next; |
||||
amp = in->amp >> 32; |
||||
in->amp += in->damp; |
||||
switch (in->type) { |
||||
case WS_SINE: |
||||
val = amp * ws->sin[in->phi >> (64 - SIN_BITS)]; |
||||
in->phi += in->dphi; |
||||
in->dphi += in->ddphi; |
||||
break; |
||||
case WS_NOISE: |
||||
val = amp * pink; |
||||
break; |
||||
default: |
||||
val = 0; |
||||
} |
||||
all_ch |= in->channels; |
||||
for (c = in->channels, cv = channels; c; c >>= 1, cv++) |
||||
if (c & 1) |
||||
*cv += val; |
||||
} |
||||
val = (int32_t)lcg_next(&ws->dither_state) >> 16; |
||||
for (c = all_ch, cv = channels; c; c >>= 1, cv++) |
||||
if (c & 1) |
||||
*cv += val; |
||||
} |
||||
|
||||
static void wavesynth_enter_intervals(struct wavesynth_context *ws, int64_t ts) |
||||
{ |
||||
int *last, i; |
||||
struct ws_interval *in; |
||||
|
||||
last = &ws->cur_inter; |
||||
for (i = ws->cur_inter; i >= 0; i = ws->inter[i].next) |
||||
last = &ws->inter[i].next; |
||||
for (i = ws->next_inter; i < ws->nb_inter; i++) { |
||||
in = &ws->inter[i]; |
||||
if (ts < in->ts_start) |
||||
break; |
||||
if (ts >= in->ts_end) |
||||
continue; |
||||
*last = i; |
||||
last = &in->next; |
||||
in->phi = in->phi0; |
||||
in->dphi = in->dphi0; |
||||
in->amp = in->amp0; |
||||
} |
||||
ws->next_inter = i; |
||||
ws->next_ts = i < ws->nb_inter ? ws->inter[i].ts_start : INF_TS; |
||||
*last = -1; |
||||
} |
||||
|
||||
static int wavesynth_decode(AVCodecContext *avc, void *rframe, int *rgot_frame, |
||||
AVPacket *packet) |
||||
{ |
||||
struct wavesynth_context *ws = avc->priv_data; |
||||
int64_t ts; |
||||
int duration; |
||||
int s, c, r; |
||||
int16_t *pcm; |
||||
int32_t channels[WS_MAX_CHANNELS]; |
||||
|
||||
*rgot_frame = 0; |
||||
if (packet->size != 12) |
||||
return AVERROR_INVALIDDATA; |
||||
ts = AV_RL64(packet->data); |
||||
if (ts != ws->cur_ts) |
||||
wavesynth_seek(ws, ts); |
||||
duration = AV_RL32(packet->data + 8); |
||||
if (duration <= 0) |
||||
return AVERROR(EINVAL); |
||||
ws->frame.nb_samples = duration; |
||||
r = avc->get_buffer(avc, &ws->frame); |
||||
if (r < 0) |
||||
return r; |
||||
pcm = (int16_t *)ws->frame.data[0]; |
||||
for (s = 0; s < duration; s++, ts++) { |
||||
memset(channels, 0, avc->channels * sizeof(*channels)); |
||||
if (ts >= ws->next_ts) |
||||
wavesynth_enter_intervals(ws, ts); |
||||
wavesynth_synth_sample(ws, ts, channels); |
||||
for (c = 0; c < avc->channels; c++) |
||||
*(pcm++) = channels[c] >> 16; |
||||
} |
||||
ws->cur_ts += duration; |
||||
*rgot_frame = 1; |
||||
*(AVFrame *)rframe = ws->frame; |
||||
return packet->size; |
||||
} |
||||
|
||||
static av_cold int wavesynth_close(AVCodecContext *avc) |
||||
{ |
||||
struct wavesynth_context *ws = avc->priv_data; |
||||
|
||||
av_free(ws->sin); |
||||
av_free(ws->inter); |
||||
return 0; |
||||
} |
||||
|
||||
AVCodec ff_ffwavesynth_decoder = { |
||||
.name = "wavesynth", |
||||
.type = AVMEDIA_TYPE_AUDIO, |
||||
.id = CODEC_ID_FFWAVESYNTH, |
||||
.priv_data_size = sizeof(struct wavesynth_context), |
||||
.init = wavesynth_init, |
||||
.close = wavesynth_close, |
||||
.decode = wavesynth_decode, |
||||
.capabilities = CODEC_CAP_DR1, |
||||
.long_name = NULL_IF_CONFIG_SMALL("Wave synthesis pseudo-codec"), |
||||
}; |
Loading…
Reference in new issue