yading@11: /*
yading@11:  * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
yading@11:  * Copyright (c) 2012 Justin Ruggles <justin.ruggles@gmail.com>
yading@11:  *
yading@11:  * This file is part of Libav.
yading@11:  *
yading@11:  * Libav is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * Libav is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with Libav; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "libavutil/common.h"
yading@11: #include "libavutil/libm.h"
yading@11: #include "libavutil/log.h"
yading@11: #include "internal.h"
yading@11: #include "resample.h"
yading@11: #include "audio_data.h"
yading@11: 
yading@11: struct ResampleContext {
yading@11:     AVAudioResampleContext *avr;
yading@11:     AudioData *buffer;
yading@11:     uint8_t *filter_bank;
yading@11:     int filter_length;
yading@11:     int ideal_dst_incr;
yading@11:     int dst_incr;
yading@11:     int index;
yading@11:     int frac;
yading@11:     int src_incr;
yading@11:     int compensation_distance;
yading@11:     int phase_shift;
yading@11:     int phase_mask;
yading@11:     int linear;
yading@11:     enum AVResampleFilterType filter_type;
yading@11:     int kaiser_beta;
yading@11:     double factor;
yading@11:     void (*set_filter)(void *filter, double *tab, int phase, int tap_count);
yading@11:     void (*resample_one)(struct ResampleContext *c, int no_filter, void *dst0,
yading@11:                          int dst_index, const void *src0, int src_size,
yading@11:                          int index, int frac);
yading@11: };
yading@11: 
yading@11: 
yading@11: /* double template */
yading@11: #define CONFIG_RESAMPLE_DBL
yading@11: #include "resample_template.c"
yading@11: #undef CONFIG_RESAMPLE_DBL
yading@11: 
yading@11: /* float template */
yading@11: #define CONFIG_RESAMPLE_FLT
yading@11: #include "resample_template.c"
yading@11: #undef CONFIG_RESAMPLE_FLT
yading@11: 
yading@11: /* s32 template */
yading@11: #define CONFIG_RESAMPLE_S32
yading@11: #include "resample_template.c"
yading@11: #undef CONFIG_RESAMPLE_S32
yading@11: 
yading@11: /* s16 template */
yading@11: #include "resample_template.c"
yading@11: 
yading@11: 
yading@11: /* 0th order modified bessel function of the first kind. */
yading@11: static double bessel(double x)
yading@11: {
yading@11:     double v     = 1;
yading@11:     double lastv = 0;
yading@11:     double t     = 1;
yading@11:     int i;
yading@11: 
yading@11:     x = x * x / 4;
yading@11:     for (i = 1; v != lastv; i++) {
yading@11:         lastv = v;
yading@11:         t    *= x / (i * i);
yading@11:         v    += t;
yading@11:     }
yading@11:     return v;
yading@11: }
yading@11: 
yading@11: /* Build a polyphase filterbank. */
yading@11: static int build_filter(ResampleContext *c)
yading@11: {
yading@11:     int ph, i;
yading@11:     double x, y, w, factor;
yading@11:     double *tab;
yading@11:     int tap_count    = c->filter_length;
yading@11:     int phase_count  = 1 << c->phase_shift;
yading@11:     const int center = (tap_count - 1) / 2;
yading@11: 
yading@11:     tab = av_malloc(tap_count * sizeof(*tab));
yading@11:     if (!tab)
yading@11:         return AVERROR(ENOMEM);
yading@11: 
yading@11:     /* if upsampling, only need to interpolate, no filter */
yading@11:     factor = FFMIN(c->factor, 1.0);
yading@11: 
yading@11:     for (ph = 0; ph < phase_count; ph++) {
yading@11:         double norm = 0;
yading@11:         for (i = 0; i < tap_count; i++) {
yading@11:             x = M_PI * ((double)(i - center) - (double)ph / phase_count) * factor;
yading@11:             if (x == 0) y = 1.0;
yading@11:             else        y = sin(x) / x;
yading@11:             switch (c->filter_type) {
yading@11:             case AV_RESAMPLE_FILTER_TYPE_CUBIC: {
yading@11:                 const float d = -0.5; //first order derivative = -0.5
yading@11:                 x = fabs(((double)(i - center) - (double)ph / phase_count) * factor);
yading@11:                 if (x < 1.0) y = 1 - 3 * x*x + 2 * x*x*x + d * (                -x*x + x*x*x);
yading@11:                 else         y =                           d * (-4 + 8 * x - 5 * x*x + x*x*x);
yading@11:                 break;
yading@11:             }
yading@11:             case AV_RESAMPLE_FILTER_TYPE_BLACKMAN_NUTTALL:
yading@11:                 w  = 2.0 * x / (factor * tap_count) + M_PI;
yading@11:                 y *= 0.3635819 - 0.4891775 * cos(    w) +
yading@11:                                  0.1365995 * cos(2 * w) -
yading@11:                                  0.0106411 * cos(3 * w);
yading@11:                 break;
yading@11:             case AV_RESAMPLE_FILTER_TYPE_KAISER:
yading@11:                 w  = 2.0 * x / (factor * tap_count * M_PI);
yading@11:                 y *= bessel(c->kaiser_beta * sqrt(FFMAX(1 - w * w, 0)));
yading@11:                 break;
yading@11:             }
yading@11: 
yading@11:             tab[i] = y;
yading@11:             norm  += y;
yading@11:         }
yading@11:         /* normalize so that an uniform color remains the same */
yading@11:         for (i = 0; i < tap_count; i++)
yading@11:             tab[i] = tab[i] / norm;
yading@11: 
yading@11:         c->set_filter(c->filter_bank, tab, ph, tap_count);
yading@11:     }
yading@11: 
yading@11:     av_free(tab);
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: ResampleContext *ff_audio_resample_init(AVAudioResampleContext *avr)
yading@11: {
yading@11:     ResampleContext *c;
yading@11:     int out_rate    = avr->out_sample_rate;
yading@11:     int in_rate     = avr->in_sample_rate;
yading@11:     double factor   = FFMIN(out_rate * avr->cutoff / in_rate, 1.0);
yading@11:     int phase_count = 1 << avr->phase_shift;
yading@11:     int felem_size;
yading@11: 
yading@11:     if (avr->internal_sample_fmt != AV_SAMPLE_FMT_S16P &&
yading@11:         avr->internal_sample_fmt != AV_SAMPLE_FMT_S32P &&
yading@11:         avr->internal_sample_fmt != AV_SAMPLE_FMT_FLTP &&
yading@11:         avr->internal_sample_fmt != AV_SAMPLE_FMT_DBLP) {
yading@11:         av_log(avr, AV_LOG_ERROR, "Unsupported internal format for "
yading@11:                "resampling: %s\n",
yading@11:                av_get_sample_fmt_name(avr->internal_sample_fmt));
yading@11:         return NULL;
yading@11:     }
yading@11:     c = av_mallocz(sizeof(*c));
yading@11:     if (!c)
yading@11:         return NULL;
yading@11: 
yading@11:     c->avr           = avr;
yading@11:     c->phase_shift   = avr->phase_shift;
yading@11:     c->phase_mask    = phase_count - 1;
yading@11:     c->linear        = avr->linear_interp;
yading@11:     c->factor        = factor;
yading@11:     c->filter_length = FFMAX((int)ceil(avr->filter_size / factor), 1);
yading@11:     c->filter_type   = avr->filter_type;
yading@11:     c->kaiser_beta   = avr->kaiser_beta;
yading@11: 
yading@11:     switch (avr->internal_sample_fmt) {
yading@11:     case AV_SAMPLE_FMT_DBLP:
yading@11:         c->resample_one  = resample_one_dbl;
yading@11:         c->set_filter    = set_filter_dbl;
yading@11:         break;
yading@11:     case AV_SAMPLE_FMT_FLTP:
yading@11:         c->resample_one  = resample_one_flt;
yading@11:         c->set_filter    = set_filter_flt;
yading@11:         break;
yading@11:     case AV_SAMPLE_FMT_S32P:
yading@11:         c->resample_one  = resample_one_s32;
yading@11:         c->set_filter    = set_filter_s32;
yading@11:         break;
yading@11:     case AV_SAMPLE_FMT_S16P:
yading@11:         c->resample_one  = resample_one_s16;
yading@11:         c->set_filter    = set_filter_s16;
yading@11:         break;
yading@11:     }
yading@11: 
yading@11:     felem_size = av_get_bytes_per_sample(avr->internal_sample_fmt);
yading@11:     c->filter_bank = av_mallocz(c->filter_length * (phase_count + 1) * felem_size);
yading@11:     if (!c->filter_bank)
yading@11:         goto error;
yading@11: 
yading@11:     if (build_filter(c) < 0)
yading@11:         goto error;
yading@11: 
yading@11:     memcpy(&c->filter_bank[(c->filter_length * phase_count + 1) * felem_size],
yading@11:            c->filter_bank, (c->filter_length - 1) * felem_size);
yading@11:     memcpy(&c->filter_bank[c->filter_length * phase_count * felem_size],
yading@11:            &c->filter_bank[(c->filter_length - 1) * felem_size], felem_size);
yading@11: 
yading@11:     c->compensation_distance = 0;
yading@11:     if (!av_reduce(&c->src_incr, &c->dst_incr, out_rate,
yading@11:                    in_rate * (int64_t)phase_count, INT32_MAX / 2))
yading@11:         goto error;
yading@11:     c->ideal_dst_incr = c->dst_incr;
yading@11: 
yading@11:     c->index = -phase_count * ((c->filter_length - 1) / 2);
yading@11:     c->frac  = 0;
yading@11: 
yading@11:     /* allocate internal buffer */
yading@11:     c->buffer = ff_audio_data_alloc(avr->resample_channels, 0,
yading@11:                                     avr->internal_sample_fmt,
yading@11:                                     "resample buffer");
yading@11:     if (!c->buffer)
yading@11:         goto error;
yading@11: 
yading@11:     av_log(avr, AV_LOG_DEBUG, "resample: %s from %d Hz to %d Hz\n",
yading@11:            av_get_sample_fmt_name(avr->internal_sample_fmt),
yading@11:            avr->in_sample_rate, avr->out_sample_rate);
yading@11: 
yading@11:     return c;
yading@11: 
yading@11: error:
yading@11:     ff_audio_data_free(&c->buffer);
yading@11:     av_free(c->filter_bank);
yading@11:     av_free(c);
yading@11:     return NULL;
yading@11: }
yading@11: 
yading@11: void ff_audio_resample_free(ResampleContext **c)
yading@11: {
yading@11:     if (!*c)
yading@11:         return;
yading@11:     ff_audio_data_free(&(*c)->buffer);
yading@11:     av_free((*c)->filter_bank);
yading@11:     av_freep(c);
yading@11: }
yading@11: 
yading@11: int avresample_set_compensation(AVAudioResampleContext *avr, int sample_delta,
yading@11:                                 int compensation_distance)
yading@11: {
yading@11:     ResampleContext *c;
yading@11:     AudioData *fifo_buf = NULL;
yading@11:     int ret = 0;
yading@11: 
yading@11:     if (compensation_distance < 0)
yading@11:         return AVERROR(EINVAL);
yading@11:     if (!compensation_distance && sample_delta)
yading@11:         return AVERROR(EINVAL);
yading@11: 
yading@11:     if (!avr->resample_needed) {
yading@11: #if FF_API_RESAMPLE_CLOSE_OPEN
yading@11:         /* if resampling was not enabled previously, re-initialize the
yading@11:            AVAudioResampleContext and force resampling */
yading@11:         int fifo_samples;
yading@11:         int restore_matrix = 0;
yading@11:         double matrix[AVRESAMPLE_MAX_CHANNELS * AVRESAMPLE_MAX_CHANNELS] = { 0 };
yading@11: 
yading@11:         /* buffer any remaining samples in the output FIFO before closing */
yading@11:         fifo_samples = av_audio_fifo_size(avr->out_fifo);
yading@11:         if (fifo_samples > 0) {
yading@11:             fifo_buf = ff_audio_data_alloc(avr->out_channels, fifo_samples,
yading@11:                                            avr->out_sample_fmt, NULL);
yading@11:             if (!fifo_buf)
yading@11:                 return AVERROR(EINVAL);
yading@11:             ret = ff_audio_data_read_from_fifo(avr->out_fifo, fifo_buf,
yading@11:                                                fifo_samples);
yading@11:             if (ret < 0)
yading@11:                 goto reinit_fail;
yading@11:         }
yading@11:         /* save the channel mixing matrix */
yading@11:         if (avr->am) {
yading@11:             ret = avresample_get_matrix(avr, matrix, AVRESAMPLE_MAX_CHANNELS);
yading@11:             if (ret < 0)
yading@11:                 goto reinit_fail;
yading@11:             restore_matrix = 1;
yading@11:         }
yading@11: 
yading@11:         /* close the AVAudioResampleContext */
yading@11:         avresample_close(avr);
yading@11: 
yading@11:         avr->force_resampling = 1;
yading@11: 
yading@11:         /* restore the channel mixing matrix */
yading@11:         if (restore_matrix) {
yading@11:             ret = avresample_set_matrix(avr, matrix, AVRESAMPLE_MAX_CHANNELS);
yading@11:             if (ret < 0)
yading@11:                 goto reinit_fail;
yading@11:         }
yading@11: 
yading@11:         /* re-open the AVAudioResampleContext */
yading@11:         ret = avresample_open(avr);
yading@11:         if (ret < 0)
yading@11:             goto reinit_fail;
yading@11: 
yading@11:         /* restore buffered samples to the output FIFO */
yading@11:         if (fifo_samples > 0) {
yading@11:             ret = ff_audio_data_add_to_fifo(avr->out_fifo, fifo_buf, 0,
yading@11:                                             fifo_samples);
yading@11:             if (ret < 0)
yading@11:                 goto reinit_fail;
yading@11:             ff_audio_data_free(&fifo_buf);
yading@11:         }
yading@11: #else
yading@11:         av_log(avr, AV_LOG_ERROR, "Unable to set resampling compensation\n");
yading@11:         return AVERROR(EINVAL);
yading@11: #endif
yading@11:     }
yading@11:     c = avr->resample;
yading@11:     c->compensation_distance = compensation_distance;
yading@11:     if (compensation_distance) {
yading@11:         c->dst_incr = c->ideal_dst_incr - c->ideal_dst_incr *
yading@11:                       (int64_t)sample_delta / compensation_distance;
yading@11:     } else {
yading@11:         c->dst_incr = c->ideal_dst_incr;
yading@11:     }
yading@11:     return 0;
yading@11: 
yading@11: reinit_fail:
yading@11:     ff_audio_data_free(&fifo_buf);
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: static int resample(ResampleContext *c, void *dst, const void *src,
yading@11:                     int *consumed, int src_size, int dst_size, int update_ctx)
yading@11: {
yading@11:     int dst_index;
yading@11:     int index         = c->index;
yading@11:     int frac          = c->frac;
yading@11:     int dst_incr_frac = c->dst_incr % c->src_incr;
yading@11:     int dst_incr      = c->dst_incr / c->src_incr;
yading@11:     int compensation_distance = c->compensation_distance;
yading@11: 
yading@11:     if (!dst != !src)
yading@11:         return AVERROR(EINVAL);
yading@11: 
yading@11:     if (compensation_distance == 0 && c->filter_length == 1 &&
yading@11:         c->phase_shift == 0) {
yading@11:         int64_t index2 = ((int64_t)index) << 32;
yading@11:         int64_t incr   = (1LL << 32) * c->dst_incr / c->src_incr;
yading@11:         dst_size       = FFMIN(dst_size,
yading@11:                                (src_size-1-index) * (int64_t)c->src_incr /
yading@11:                                c->dst_incr);
yading@11: 
yading@11:         if (dst) {
yading@11:             for(dst_index = 0; dst_index < dst_size; dst_index++) {
yading@11:                 c->resample_one(c, 1, dst, dst_index, src, 0, index2 >> 32, 0);
yading@11:                 index2 += incr;
yading@11:             }
yading@11:         } else {
yading@11:             dst_index = dst_size;
yading@11:         }
yading@11:         index += dst_index * dst_incr;
yading@11:         index += (frac + dst_index * (int64_t)dst_incr_frac) / c->src_incr;
yading@11:         frac   = (frac + dst_index * (int64_t)dst_incr_frac) % c->src_incr;
yading@11:     } else {
yading@11:         for (dst_index = 0; dst_index < dst_size; dst_index++) {
yading@11:             int sample_index = index >> c->phase_shift;
yading@11: 
yading@11:             if (sample_index + c->filter_length > src_size ||
yading@11:                 -sample_index >= src_size)
yading@11:                 break;
yading@11: 
yading@11:             if (dst)
yading@11:                 c->resample_one(c, 0, dst, dst_index, src, src_size, index, frac);
yading@11: 
yading@11:             frac  += dst_incr_frac;
yading@11:             index += dst_incr;
yading@11:             if (frac >= c->src_incr) {
yading@11:                 frac -= c->src_incr;
yading@11:                 index++;
yading@11:             }
yading@11:             if (dst_index + 1 == compensation_distance) {
yading@11:                 compensation_distance = 0;
yading@11:                 dst_incr_frac = c->ideal_dst_incr % c->src_incr;
yading@11:                 dst_incr      = c->ideal_dst_incr / c->src_incr;
yading@11:             }
yading@11:         }
yading@11:     }
yading@11:     if (consumed)
yading@11:         *consumed = FFMAX(index, 0) >> c->phase_shift;
yading@11: 
yading@11:     if (update_ctx) {
yading@11:         if (index >= 0)
yading@11:             index &= c->phase_mask;
yading@11: 
yading@11:         if (compensation_distance) {
yading@11:             compensation_distance -= dst_index;
yading@11:             if (compensation_distance <= 0)
yading@11:                 return AVERROR_BUG;
yading@11:         }
yading@11:         c->frac     = frac;
yading@11:         c->index    = index;
yading@11:         c->dst_incr = dst_incr_frac + c->src_incr*dst_incr;
yading@11:         c->compensation_distance = compensation_distance;
yading@11:     }
yading@11: 
yading@11:     return dst_index;
yading@11: }
yading@11: 
yading@11: int ff_audio_resample(ResampleContext *c, AudioData *dst, AudioData *src)
yading@11: {
yading@11:     int ch, in_samples, in_leftover, consumed = 0, out_samples = 0;
yading@11:     int ret = AVERROR(EINVAL);
yading@11: 
yading@11:     in_samples  = src ? src->nb_samples : 0;
yading@11:     in_leftover = c->buffer->nb_samples;
yading@11: 
yading@11:     /* add input samples to the internal buffer */
yading@11:     if (src) {
yading@11:         ret = ff_audio_data_combine(c->buffer, in_leftover, src, 0, in_samples);
yading@11:         if (ret < 0)
yading@11:             return ret;
yading@11:     } else if (!in_leftover) {
yading@11:         /* no remaining samples to flush */
yading@11:         return 0;
yading@11:     } else {
yading@11:         /* TODO: pad buffer to flush completely */
yading@11:     }
yading@11: 
yading@11:     /* calculate output size and reallocate output buffer if needed */
yading@11:     /* TODO: try to calculate this without the dummy resample() run */
yading@11:     if (!dst->read_only && dst->allow_realloc) {
yading@11:         out_samples = resample(c, NULL, NULL, NULL, c->buffer->nb_samples,
yading@11:                                INT_MAX, 0);
yading@11:         ret = ff_audio_data_realloc(dst, out_samples);
yading@11:         if (ret < 0) {
yading@11:             av_log(c->avr, AV_LOG_ERROR, "error reallocating output\n");
yading@11:             return ret;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     /* resample each channel plane */
yading@11:     for (ch = 0; ch < c->buffer->channels; ch++) {
yading@11:         out_samples = resample(c, (void *)dst->data[ch],
yading@11:                                (const void *)c->buffer->data[ch], &consumed,
yading@11:                                c->buffer->nb_samples, dst->allocated_samples,
yading@11:                                ch + 1 == c->buffer->channels);
yading@11:     }
yading@11:     if (out_samples < 0) {
yading@11:         av_log(c->avr, AV_LOG_ERROR, "error during resampling\n");
yading@11:         return out_samples;
yading@11:     }
yading@11: 
yading@11:     /* drain consumed samples from the internal buffer */
yading@11:     ff_audio_data_drain(c->buffer, consumed);
yading@11: 
yading@11:     av_dlog(c->avr, "resampled %d in + %d leftover to %d out + %d leftover\n",
yading@11:             in_samples, in_leftover, out_samples, c->buffer->nb_samples);
yading@11: 
yading@11:     dst->nb_samples = out_samples;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: int avresample_get_delay(AVAudioResampleContext *avr)
yading@11: {
yading@11:     if (!avr->resample_needed || !avr->resample)
yading@11:         return 0;
yading@11: 
yading@11:     return avr->resample->buffer->nb_samples;
yading@11: }