Add tinycap utility to capture PCM riff/wave files

This adds a utility to capture audio with a specified number of
parameters. Capturing continues until a signal is received
(ctrl-c).

Contains some contributions from Chris Kelly <c-kelly@ti.com>

1 files changed, 191 insertions, 0 deletions

diff --git a/tinycap.c b/tinycap.c
new file mode 100644
index 0000000..c5ffd33
--- /dev/null
+++ b/tinycap.c
@@ -0,0 +1,191 @@
+/* tinycap.c
+**
+** Copyright 2011, The Android Open Source Project
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are met:
+**     * Redistributions of source code must retain the above copyright
+**       notice, this list of conditions and the following disclaimer.
+**     * Redistributions in binary form must reproduce the above copyright
+**       notice, this list of conditions and the following disclaimer in the
+**       documentation and/or other materials provided with the distribution.
+**     * Neither the name of The Android Open Source Project nor the names of
+**       its contributors may be used to endorse or promote products derived
+**       from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY The Android Open Source Project ``AS IS'' AND
+** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+** ARE DISCLAIMED. IN NO EVENT SHALL The Android Open Source Project BE LIABLE
+** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+** SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+** DAMAGE.
+*/
+
+#include <tinyalsa/asoundlib.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <signal.h>
+
+#define ID_RIFF 0x46464952
+#define ID_WAVE 0x45564157
+#define ID_FMT  0x20746d66
+#define ID_DATA 0x61746164
+
+#define FORMAT_PCM 1
+
+struct wav_header {
+    uint32_t riff_id;
+    uint32_t riff_sz;
+    uint32_t riff_fmt;
+    uint32_t fmt_id;
+    uint32_t fmt_sz;
+    uint16_t audio_format;
+    uint16_t num_channels;
+    uint32_t sample_rate;
+    uint32_t byte_rate;
+    uint16_t block_align;
+    uint16_t bits_per_sample;
+    uint32_t data_id;
+    uint32_t data_sz;
+};
+
+int capturing = 1;
+
+unsigned int capture_sample(FILE *file, unsigned int device,
+                            unsigned int channels, unsigned int rate,
+                            unsigned int bits);
+
+void sigint_handler(int sig)
+{
+    capturing = 0;
+}
+
+int main(int argc, char **argv)
+{
+    FILE *file;
+    struct wav_header header;
+    unsigned int device = 0;
+    unsigned int channels = 2;
+    unsigned int rate = 44100;
+    unsigned int bits = 16;
+    unsigned int frames;
+
+    if (argc < 2) {
+        fprintf(stderr, "Usage: %s file.wav [-d device] [-c channels] "
+                "[-r rate] [-b bits]\n", argv[0]);
+        return 1;
+    }
+
+    file = fopen(argv[1], "wb");
+    if (!file) {
+        fprintf(stderr, "Unable to create file '%s'\n", argv[1]);
+        return 1;
+    }
+
+    /* parse command line arguments */
+    argv += 2;
+    while (*argv) {
+        if (strcmp(*argv, "-d", 2) == 0) {
+            argv++;
+            device = atoi(*argv);
+        } else if (strcmp(*argv, "-c", 2) == 0) {
+            argv++;
+            channels = atoi(*argv);
+        } else if (strcmp(*argv, "-r", 2) == 0) {
+            argv++;
+            rate = atoi(*argv);
+        } else if (strcmp(*argv, "-b", 2) == 0) {
+            argv++;
+            bits = atoi(*argv);
+        }
+        argv++;
+    }
+
+    header.riff_id = ID_RIFF;
+    header.riff_sz = 0;
+    header.riff_fmt = ID_WAVE;
+    header.fmt_id = ID_FMT;
+    header.fmt_sz = 16;
+    header.audio_format = FORMAT_PCM;
+    header.num_channels = channels;
+    header.sample_rate = rate;
+    header.byte_rate = (header.bits_per_sample / 8) * channels * rate;
+    header.block_align = channels * (header.bits_per_sample / 8);
+    header.bits_per_sample = bits;
+    header.data_id = ID_DATA;
+
+    /* leave enough room for header */
+    fseek(file, sizeof(struct wav_header), SEEK_SET);
+
+    /* install signal handler and begin capturing */
+    signal(SIGINT, sigint_handler);
+    frames = capture_sample(file, device, header.num_channels,
+                            header.sample_rate, header.bits_per_sample);
+    printf("Captured %d frames\n", frames);
+
+    /* write header now all information is known */
+    header.data_sz = frames * header.block_align;
+    fseek(file, 0, SEEK_SET);
+    fwrite(&header, sizeof(struct wav_header), 1, file);
+
+    fclose(file);
+
+    return 0;
+}
+
+unsigned int capture_sample(FILE *file, unsigned int device,
+                            unsigned int channels, unsigned int rate,
+                            unsigned int bits)
+{
+    struct pcm_config config;
+    struct pcm *pcm;
+    char *buffer;
+    unsigned int size;
+    unsigned int bytes_read = 0;
+
+    config.channels = channels;
+    config.rate = rate;
+    config.period_size = 1024;
+    config.period_count = 4;
+    if (bits == 32)
+        config.format = PCM_FORMAT_S32_LE;
+    else if (bits == 16)
+        config.format = PCM_FORMAT_S16_LE;
+
+    pcm = pcm_open(0, device, PCM_IN, &config);
+    if (!pcm || !pcm_is_ready(pcm)) {
+        fprintf(stderr, "Unable to open PCM device (%s)\n",
+                pcm_get_error(pcm));
+        return 0;
+    }
+
+    size = pcm_get_buffer_size(pcm);
+    buffer = malloc(size);
+    if (!buffer) {
+        fprintf(stderr, "Unable to allocate %d bytes\n", size);
+        free(buffer);
+        pcm_close(pcm);
+        return 0;
+    }
+
+    printf("Capturing sample: %u ch, %u hz, %u bit\n", channels, rate, bits);
+
+    while (capturing && !pcm_read(pcm, buffer, size)) {
+        if (fwrite(buffer, 1, size, file) != size) {
+            fprintf(stderr,"Error capturing sample\n");
+            break;
+        }
+        bytes_read += size;
+    }
+
+    free(buffer);
+    pcm_close(pcm);
+    return bytes_read / ((bits / 8) * channels);
+}
+