| /* $Id$ */ |
| /* |
| * 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 */ |
| |