crec: support streaming output to stdout

It's useful for testing to be able to stream the captured
audio to stdout instead of having to go via a file.

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Ammar Ali <aali@opensource.wolfsonmicro.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/crec.c b/crec.c
index e3f189f41448ef36074b58d67e820a36db21b072..258fadee51b813f8a5ba246c195832c6edb62713 100644 (file)
--- a/crec.c
+++ b/crec.c
@@ -77,6 +77,8 @@
 
 static int verbose;
 static int file;
+static FILE *finfo;
+static bool streamed;
 
 static const unsigned int DEFAULT_CHANNELS = 1;
 static const unsigned int DEFAULT_RATE = 44100;
@@ -151,7 +153,7 @@ static void size_wave_header(struct wave_header *header, uint32_t size)
 
 static void usage(void)
 {
-       fprintf(stderr, "usage: crec [OPTIONS] filename\n"
+       fprintf(stderr, "usage: crec [OPTIONS] [filename]\n"
                "-c\tcard number\n"
                "-d\tdevice node\n"
                "-b\tbuffer size\n"
@@ -162,6 +164,8 @@ static void usage(void)
                "-C\tSpecify the number of channels (default %u)\n"
                "-R\tSpecify the sample rate (default %u)\n"
                "-F\tSpecify the format: S16_LE, S32_LE (default S16_LE)\n\n"
+               "If filename is not given the output is\n"
+               "written to stdout\n\n"
                "Example:\n"
                "\tcrec -c 1 -d 2 test.wav\n"
                "\tcrec -f 5 test.wav\n",
@@ -180,7 +184,7 @@ static int print_time(struct compress *compress)
                fprintf(stderr, "ERR: %s\n", compress_get_error(compress));
                return -1;
        } else {
-               printf("DSP recorded %jd.%jd\n",
+               fprintf(finfo, "DSP recorded %jd.%jd\n",
                       (intmax_t)tstamp.tv_sec, (intmax_t)tstamp.tv_nsec*1000);
        }
        return 0;
@@ -195,6 +199,10 @@ static int finish_record()
        if (!file)
                return -ENOENT;
 
+       /* can't rewind if streaming to stdout */
+       if (streamed)
+               return 0;
+
        /* Get amount of data written to file */
        ret = lseek(file, 0, SEEK_END);
        if (ret < 0)
@@ -256,22 +264,27 @@ void capture_samples(char *name, unsigned int card, unsigned int device,
        length = length * rate * (samplebits / 8) * channels;
 
        if (verbose)
-               printf("%s: entry, reading %u bytes\n", __func__, length);
-
-       file = open(name, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
-       if (file == -1) {
-               fprintf(stderr, "Unable to open file '%s'\n", name);
-               exit(EXIT_FAILURE);
-       }
+               fprintf(finfo, "%s: entry, reading %u bytes\n", __func__, length);
+        if (!name) {
+                file = STDOUT_FILENO;
+        } else {
+               file = open(name, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+               if (file == -1) {
+                      fprintf(stderr, "Unable to open file '%s'\n", name);
+                      exit(EXIT_FAILURE);
+               }
+        }
 
        /* Write a header, will update with size once record is complete */
-       init_wave_header(&header, channels, rate, samplebits);
-       written = write(file, &header, sizeof(header));
-       if (written != sizeof(header)) {
+        if (!streamed) {
+           init_wave_header(&header, channels, rate, samplebits);
+           written = write(file, &header, sizeof(header));
+           if (written != sizeof(header)) {
                fprintf(stderr, "Error writing output file header: %s\n",
                        strerror(errno));
                goto file_exit;
-       }
+           }
+        }
 
        memset(&codec, 0, sizeof(codec));
        memset(&config, 0, sizeof(config));
@@ -299,7 +312,7 @@ void capture_samples(char *name, unsigned int card, unsigned int device,
        };
 
        if (verbose)
-               printf("%s: Opened compress device\n", __func__);
+               fprintf(finfo, "%s: Opened compress device\n", __func__);
 
        size = config.fragment_size;
        buffer = malloc(size * config.fragments);
@@ -308,15 +321,15 @@ void capture_samples(char *name, unsigned int card, unsigned int device,
                goto comp_exit;
        }
 
-       printf("Recording file %s On Card %u device %u, with buffer of %lu bytes\n",
+       fprintf(finfo, "Recording file %s On Card %u device %u, with buffer of %lu bytes\n",
               name, card, device, buffer_size);
-       printf("Format %u Channels %u, %u Hz\n",
-              codec.id, codec.ch_out, rate);
+       fprintf(finfo, "Codec %u Format %u Channels %u, %u Hz\n",
+              codec.id, codec.format, codec.ch_out, rate);
 
        compress_start(compress);
 
        if (verbose)
-               printf("%s: Capturing audio NOW!!!\n", __func__);
+               fprintf(finfo, "%s: Capturing audio NOW!!!\n", __func__);
 
        do {
                if (length && size > length - total_read)
@@ -344,7 +357,7 @@ void capture_samples(char *name, unsigned int card, unsigned int device,
                        }
                        if (verbose) {
                                print_time(compress);
-                               printf("%s: read %d\n", __func__, read);
+                               fprintf(finfo, "%s: read %d\n", __func__, read);
                        }
                }
        } while (!length || total_read < length);
@@ -362,7 +375,7 @@ void capture_samples(char *name, unsigned int card, unsigned int device,
        }
 
        if (verbose)
-               printf("%s: exit success\n", __func__);
+               fprintf(finfo, "%s: exit success\n", __func__);
 
        free(buffer);
        close(file);
@@ -379,7 +392,7 @@ file_exit:
        close(file);
 
        if (verbose)
-               printf("%s: exit failure\n", __func__);
+               fprintf(finfo, "%s: exit failure\n", __func__);
 
        exit(EXIT_FAILURE);
 }
@@ -408,7 +421,7 @@ int main(int argc, char **argv)
                exit(EXIT_FAILURE);
        }
 
-       if (argc < 2)
+       if (argc < 1)
                usage();
 
        verbose = 0;
@@ -456,15 +469,21 @@ int main(int argc, char **argv)
                        exit(EXIT_FAILURE);
                }
        }
-       if (optind >= argc)
-               usage();
-
-       file = argv[optind];
+       if (optind >= argc) {
+               file = NULL;
+               finfo = fopen("/dev/null", "w");
+               streamed = true;
+       } else {
+               file = argv[optind];
+               finfo = stdout;
+               streamed = false;
+       }
 
        capture_samples(file, card, device, buffer_size, frag, length,
                        rate, channels, format);
 
-       printf("Finish capturing... Close Normally\n");
+       fprintf(finfo, "Finish capturing... Close Normally\n");
+
        exit(EXIT_SUCCESS);
 }