diff options
Diffstat (limited to 'pjmedia/src/pjmedia/resample_resample.c')
-rw-r--r-- | pjmedia/src/pjmedia/resample_resample.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/pjmedia/src/pjmedia/resample_resample.c b/pjmedia/src/pjmedia/resample_resample.c new file mode 100644 index 0000000..e1a1b0d --- /dev/null +++ b/pjmedia/src/pjmedia/resample_resample.c @@ -0,0 +1,346 @@ +/* $Id: resample_resample.c 3553 2011-05-05 06:14:19Z nanang $ */ +/* + * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com) + * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <pjmedia/resample.h> + +#include <pjmedia/errno.h> +#include <pj/assert.h> +#include <pj/log.h> +#include <pj/pool.h> + + +#if PJMEDIA_RESAMPLE_IMP==PJMEDIA_RESAMPLE_LIBRESAMPLE + +#include <third_party/resample/include/resamplesubs.h> + +#define THIS_FILE "resample.c" + + + +struct pjmedia_resample +{ + double factor; /* Conversion factor = rate_out / rate_in. */ + pj_bool_t large_filter; /* Large filter? */ + pj_bool_t high_quality; /* Not fast? */ + unsigned xoff; /* History and lookahead size, in samples */ + unsigned frame_size; /* Samples per frame. */ + unsigned channel_cnt; /* Channel count. */ + + /* Buffer for monochannel */ + pj_int16_t *buffer; /* Input buffer. */ + + /* Buffer for multichannel */ + pj_int16_t **in_buffer; /* Array of input buffer for each channel. */ + pj_int16_t *tmp_buffer; /* Temporary output buffer for processing. */ +}; + + +PJ_DEF(pj_status_t) pjmedia_resample_create( pj_pool_t *pool, + pj_bool_t high_quality, + pj_bool_t large_filter, + unsigned channel_count, + unsigned rate_in, + unsigned rate_out, + unsigned samples_per_frame, + pjmedia_resample **p_resample) +{ + pjmedia_resample *resample; + + PJ_ASSERT_RETURN(pool && p_resample && rate_in && + rate_out && samples_per_frame, PJ_EINVAL); + + resample = PJ_POOL_ZALLOC_T(pool, pjmedia_resample); + PJ_ASSERT_RETURN(resample, PJ_ENOMEM); + + /* + * If we're downsampling, always use the fast algorithm since it seems + * to yield the same quality. + */ + if (rate_out < rate_in) { + //no this is not a good idea. It sounds pretty good with speech, + //but very poor with background noise etc. + //high_quality = 0; + } + + resample->factor = rate_out * 1.0 / rate_in; + resample->large_filter = large_filter; + resample->high_quality = high_quality; + resample->channel_cnt = channel_count; + resample->frame_size = samples_per_frame; + + if (high_quality) { + /* This is a bug in xoff calculation, thanks Stephane Lussier + * of Macadamian dot com. + * resample->xoff = large_filter ? 32 : 6; + */ + resample->xoff = res_GetXOFF(resample->factor, (char)large_filter); + } else { + resample->xoff = 1; + } + + if (channel_count == 1) { + unsigned size; + + /* Allocate input buffer */ + size = (samples_per_frame + 2*resample->xoff) * sizeof(pj_int16_t); + resample->buffer = (pj_int16_t*) pj_pool_alloc(pool, size); + PJ_ASSERT_RETURN(resample->buffer, PJ_ENOMEM); + + pjmedia_zero_samples(resample->buffer, resample->xoff*2); + + } else if (channel_count > 1) { + unsigned i, size; + + /* Allocate input buffer table */ + size = channel_count * sizeof(pj_int16_t*); + resample->in_buffer = (pj_int16_t**)pj_pool_alloc(pool, size); + + /* Allocate input buffer */ + size = (samples_per_frame/channel_count + 2*resample->xoff) * + sizeof(pj_int16_t); + for (i = 0; i < channel_count; ++i) { + resample->in_buffer[i] = (pj_int16_t*)pj_pool_alloc(pool, size); + PJ_ASSERT_RETURN(resample->in_buffer, PJ_ENOMEM); + pjmedia_zero_samples(resample->in_buffer[i], resample->xoff*2); + } + + /* Allocate temporary output buffer */ + size = (unsigned) (resample->frame_size * sizeof(pj_int16_t) * + resample->factor / channel_count + 0.5); + resample->tmp_buffer = (pj_int16_t*) pj_pool_alloc(pool, size); + PJ_ASSERT_RETURN(resample->tmp_buffer, PJ_ENOMEM); + } + + *p_resample = resample; + + PJ_LOG(5,(THIS_FILE, "resample created: %s qualiy, %s filter, in/out " + "rate=%d/%d", + (high_quality?"high":"low"), + (large_filter?"large":"small"), + rate_in, rate_out)); + return PJ_SUCCESS; +} + + + +PJ_DEF(void) pjmedia_resample_run( pjmedia_resample *resample, + const pj_int16_t *input, + pj_int16_t *output ) +{ + PJ_ASSERT_ON_FAIL(resample, return); + + /* Okay chaps, here's how we do resampling. + * + * The original resample algorithm requires xoff samples *before* the + * input buffer as history, and another xoff samples *after* the + * end of the input buffer as lookahead. Since application can only + * supply framesize buffer on each run, PJMEDIA needs to arrange the + * buffer to meet these requirements. + * + * So here comes the trick. + * + * First of all, because of the history and lookahead requirement, + * resample->buffer need to accomodate framesize+2*xoff samples in its + * buffer. This is done when the buffer is created. + * + * On the first run, the input frame (supplied by application) is + * copied to resample->buffer at 2*xoff position. The first 2*xoff + * samples are initially zeroed (in the initialization). The resample + * algorithm then invoked at resample->buffer+xoff ONLY, thus giving + * it one xoff at the beginning as zero, and one xoff at the end + * as the end of the original input. The resample algorithm will see + * that the first xoff samples in the input as zero. + * + * So here's the layout of resample->buffer on the first run. + * + * run 0 + * +------+------+--------------+ + * | 0000 | 0000 | frame0... | + * +------+------+--------------+ + * ^ ^ ^ ^ + * 0 xoff 2*xoff size+2*xoff + * + * (Note again: resample algorithm is called at resample->buffer+xoff) + * + * At the end of the run, 2*xoff samples from the end of + * resample->buffer are copied to the beginning of resample->buffer. + * The first xoff part of this will be used as history for the next + * run, and the second xoff part of this is actually the start of + * resampling for the next run. + * + * And the first run completes, the function returns. + * + * + * On the next run, the input frame supplied by application is again + * copied at 2*xoff position in the resample->buffer, and the + * resample algorithm is again invoked at resample->buffer+xoff + * position. So effectively, the resample algorithm will start its + * operation on the last xoff from the previous frame, and gets the + * history from the last 2*xoff of the previous frame, and the look- + * ahead from the last xoff of current frame. + * + * So on this run, the buffer layout is: + * + * run 1 + * +------+------+--------------+ + * | frm0 | frm0 | frame1... | + * +------+------+--------------+ + * ^ ^ ^ ^ + * 0 xoff 2*xoff size+2*xoff + * + * As you can see from above diagram, the resampling algorithm is + * actually called from the last xoff part of previous frame (frm0). + * + * And so on the process continues for the next frame, and the next, + * and the next, ... + * + */ + if (resample->channel_cnt == 1) { + pj_int16_t *dst_buf; + const pj_int16_t *src_buf; + + /* Prepare input frame */ + dst_buf = resample->buffer + resample->xoff*2; + pjmedia_copy_samples(dst_buf, input, resample->frame_size); + + /* Resample */ + if (resample->high_quality) { + res_Resample(resample->buffer + resample->xoff, output, + resample->factor, (pj_uint16_t)resample->frame_size, + (char)resample->large_filter, (char)PJ_TRUE); + } else { + res_SrcLinear(resample->buffer + resample->xoff, output, + resample->factor, (pj_uint16_t)resample->frame_size); + } + + /* Update history */ + dst_buf = resample->buffer; + src_buf = input + resample->frame_size - resample->xoff*2; + pjmedia_copy_samples(dst_buf, src_buf, resample->xoff * 2); + + } else { /* Multichannel */ + unsigned i, j; + + for (i = 0; i < resample->channel_cnt; ++i) { + pj_int16_t *dst_buf; + const pj_int16_t *src_buf; + unsigned mono_frm_sz_in; + unsigned mono_frm_sz_out; + + mono_frm_sz_in = resample->frame_size / resample->channel_cnt; + mono_frm_sz_out = (unsigned)(mono_frm_sz_in * resample->factor + 0.5); + + /* Deinterleave input */ + dst_buf = resample->in_buffer[i] + resample->xoff*2; + src_buf = input + i; + for (j = 0; j < mono_frm_sz_in; ++j) { + *dst_buf++ = *src_buf; + src_buf += resample->channel_cnt; + } + + /* Resample this channel */ + if (resample->high_quality) { + res_Resample(resample->in_buffer[i] + resample->xoff, + resample->tmp_buffer, resample->factor, + (pj_uint16_t)mono_frm_sz_in, + (char)resample->large_filter, (char)PJ_TRUE); + } else { + res_SrcLinear( resample->in_buffer[i], + resample->tmp_buffer, + resample->factor, + (pj_uint16_t)mono_frm_sz_in); + } + + /* Update history */ + dst_buf = resample->in_buffer[i]; + src_buf = resample->in_buffer[i] + mono_frm_sz_in; + pjmedia_copy_samples(dst_buf, src_buf, resample->xoff * 2); + + /* Reinterleave output */ + dst_buf = output + i; + src_buf = resample->tmp_buffer; + for (j = 0; j < mono_frm_sz_out; ++j) { + *dst_buf = *src_buf++; + dst_buf += resample->channel_cnt; + } + } + } +} + +PJ_DEF(unsigned) pjmedia_resample_get_input_size(pjmedia_resample *resample) +{ + PJ_ASSERT_RETURN(resample != NULL, 0); + return resample->frame_size; +} + +PJ_DEF(void) pjmedia_resample_destroy(pjmedia_resample *resample) +{ + PJ_UNUSED_ARG(resample); +} + + +#elif PJMEDIA_RESAMPLE_IMP==PJMEDIA_RESAMPLE_NONE + +/* + * This is the configuration when sample rate conversion is disabled. + */ +PJ_DEF(pj_status_t) pjmedia_resample_create( pj_pool_t *pool, + pj_bool_t high_quality, + pj_bool_t large_filter, + unsigned channel_count, + unsigned rate_in, + unsigned rate_out, + unsigned samples_per_frame, + pjmedia_resample **p_resample) +{ + PJ_UNUSED_ARG(pool); + PJ_UNUSED_ARG(high_quality); + PJ_UNUSED_ARG(large_filter); + PJ_UNUSED_ARG(channel_count); + PJ_UNUSED_ARG(rate_in); + PJ_UNUSED_ARG(rate_out); + PJ_UNUSED_ARG(samples_per_frame); + PJ_UNUSED_ARG(p_resample); + + return PJ_EINVALIDOP; +} + +PJ_DEF(void) pjmedia_resample_run( pjmedia_resample *resample, + const pj_int16_t *input, + pj_int16_t *output ) +{ + PJ_UNUSED_ARG(resample); + PJ_UNUSED_ARG(input); + PJ_UNUSED_ARG(output); +} + +PJ_DEF(unsigned) pjmedia_resample_get_input_size(pjmedia_resample *resample) +{ + PJ_UNUSED_ARG(resample); + return 0; +} + +PJ_DEF(void) pjmedia_resample_destroy(pjmedia_resample *resample) +{ + PJ_UNUSED_ARG(resample); +} + +#endif /* PJMEDIA_RESAMPLE_IMP */ + |