Samples: Mixing WAV files

This file is pjsip-apps/src/samples/mix.c

/* 
 * 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 <pjlib.h>
#include <pjlib-util.h>
#include <pjmedia.h>
 
#define THIS_FILE   "mix.c"
 
static const char *desc = 
 " mix\n"
 "\n"
 " PURPOSE:\n"
 "  Mix input WAV files and save it to output WAV. Input WAV can have\n"
 "  different clock rate.\n"
 "\n"
 "\n"
 " USAGE:\n"
 "  mix [options] output.wav input1.wav [input2.wav] ...\n"
 "\n"
 " arguments:\n"
 "    output.wav    Set the output WAV filename.\n"
 "    input1.wav    Set the input WAV filename.\n"
 "    input2.wav    Set the input WAV filename.\n"
 "\n"
 " options:\n"
 "    -c N          Set clock rate to N Hz (default 16000)\n"
 "    -f            Force write (overwrite output without warning\n"
;
 
#define MAX_WAV     16
#define PTIME       20
#define APPEND      1000
 
struct wav_input
{
    const char      *fname;
    pjmedia_port    *port;
    unsigned         slot;
};
 
static int err_ret(const char *title, pj_status_t status)
{
    char errmsg[PJ_ERR_MSG_SIZE];
    pj_strerror(status, errmsg, sizeof(errmsg));
    PJ_LOG(3,(THIS_FILE, "%s error: %s", title, errmsg));
    return 1;
}
 
static void usage(void)
{
    puts(desc);
}
 
int main(int argc, char *argv[])
{
    pj_caching_pool cp;
    pj_pool_t *pool;
    pjmedia_endpt *med_ept;
    unsigned clock_rate = 16000;
    int c, force=0;
    const char *out_fname;
    pjmedia_conf *conf;
    pjmedia_port *wavout;
    struct wav_input wav_input[MAX_WAV];
    pj_size_t longest = 0, processed;
    unsigned i, input_cnt = 0;
    pj_status_t status;
 
#define CHECK(op)   do { \
                        status = op; \
                        if (status != PJ_SUCCESS) \
                            return err_ret(#op, status); \
                    } while (0)
 
 
    /* Parse arguments */
    while ((c=pj_getopt(argc, argv, "c:f")) != -1) {
        switch (c) {
        case 'c':
            clock_rate = atoi(pj_optarg);
            if (clock_rate < 1000) {
                puts("Error: invalid clock rate");
                usage();
                return -1;
            }
            break;
        case 'f':
            force = 1;
            break;
        }
    }
 
    /* Get output WAV name */
    if (pj_optind == argc) {
        puts("Error: no WAV output is specified");
        usage();
        return 1;
    }
 
    out_fname = argv[pj_optind++];
    if (force==0 && pj_file_exists(out_fname)) {
        char in[8];
 
        printf("File %s exists, overwrite? [Y/N] ", out_fname);
        fflush(stdout);
        if (fgets(in, sizeof(in), stdin) == NULL)
            return 1;
        if (pj_tolower(in[0]) != 'y')
            return 1;
    }
 
    /* Scan input file names */
    for (input_cnt=0 ; pj_optind<argc && input_cnt<MAX_WAV; 
         ++pj_optind, ++input_cnt) 
    {
        if (!pj_file_exists(argv[pj_optind])) {
            printf("Error: input file %s doesn't exist\n",
                   argv[pj_optind]);
            return 1;
        }
        wav_input[input_cnt].fname = argv[pj_optind];
        wav_input[input_cnt].port = NULL;
        wav_input[input_cnt].slot = 0;
    }
 
    if (input_cnt == 0) {
        puts("Error: no input WAV is specified");
        return 0;
    }
 
    /* Initialialize */
    CHECK( pj_init() );
    CHECK( pjlib_util_init() );
    pj_caching_pool_init(&cp, NULL, 0);
    CHECK( pjmedia_endpt_create(&cp.factory, NULL, 1, &med_ept) );
 
    pool = pj_pool_create(&cp.factory, "mix", 1000, 1000, NULL);
 
    /* Create the bridge */
    CHECK( pjmedia_conf_create(pool, MAX_WAV+4, clock_rate, 1, 
                               clock_rate * PTIME / 1000, 16, 
                               PJMEDIA_CONF_NO_DEVICE, &conf) );
 
    /* Create the WAV output */
    CHECK( pjmedia_wav_writer_port_create(pool, out_fname, clock_rate, 1,
                                          clock_rate * PTIME / 1000,
                                          16, 0, 0, &wavout) );
 
    /* Create and register each WAV input to the bridge */
    for (i=0; i<input_cnt; ++i) {
        pj_ssize_t len;
 
        CHECK( pjmedia_wav_player_port_create(pool, wav_input[i].fname, 20,
                                              PJMEDIA_FILE_NO_LOOP, 0, 
                                              &wav_input[i].port) );
        len = pjmedia_wav_player_get_len(wav_input[i].port);
        len = (pj_ssize_t)(len * 1.0 * clock_rate / 
                           PJMEDIA_PIA_SRATE(&wav_input[i].port->info));
        if (len > (pj_ssize_t)longest)
            longest = len;
 
        CHECK( pjmedia_conf_add_port(conf, pool, wav_input[i].port,
                                     NULL, &wav_input[i].slot));
 
        CHECK( pjmedia_conf_connect_port(conf, wav_input[i].slot, 0, 0) );
    }
 
    /* Loop reading frame from the bridge and write it to WAV */
    processed = 0;
    while (processed < longest + clock_rate * APPEND * 2 / 1000) {
        pj_int16_t framebuf[PTIME * 48000 / 1000];
        pjmedia_port *mp = pjmedia_conf_get_master_port(conf);
        pjmedia_frame frame;
 
        frame.buf = framebuf;
        frame.size = PJMEDIA_PIA_SPF(&mp->info) * 2;
        pj_assert(frame.size <= sizeof(framebuf));
        
        CHECK( pjmedia_port_get_frame(mp, &frame) );
 
        if (frame.type != PJMEDIA_FRAME_TYPE_AUDIO) {
            pj_bzero(frame.buf, frame.size);
            frame.type = PJMEDIA_FRAME_TYPE_AUDIO;
        }
 
        CHECK( pjmedia_port_put_frame(wavout, &frame));
 
        processed += frame.size;
    }
 
    PJ_LOG(3,(THIS_FILE, "Done. Output duration: %d.%03d",
              (processed >> 2)/clock_rate,
              ((processed >> 2)*1000/clock_rate) % 1000));
 
    /* Shutdown everything */
    CHECK( pjmedia_port_destroy(wavout) );
    for (i=0; i<input_cnt; ++i) {
        CHECK( pjmedia_conf_remove_port(conf, wav_input[i].slot) );
        CHECK( pjmedia_port_destroy(wav_input[i].port) );
    }
 
    CHECK(pjmedia_conf_destroy(conf));
    CHECK(pjmedia_endpt_destroy(med_ept));
 
    pj_pool_release(pool);
    pj_caching_pool_destroy(&cp);
    pj_shutdown();
 
    return 0;
}