utils: cplay: Add support for pause/resume

We want to be able to pause and resume the stream
just like the ALSA utilitary aplay does.

In order to do so, we first need to mark the read operations
on stdin as nonblocking and then enable the noncanonical mode
for the terminal. What this does is it makes the read operations
nonblocking and it makes the input available immediately.

After doing so, we can check if we receive a SPACE or ENTER
character from user and do pause/resume depending on current
stream state (and by this I mean if the stream is currently
paused and we receive a SPACE or ENTER then we resume it
and vice-versa)

Signed-off-by: Maurine Creton <maurine.creton@nxp.com>
Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

diff --git a/src/utils/cplay.c b/src/utils/cplay.c
index 4604c36956703e689d740afe1fc1a43df4c5979d..790408b67d0e01ef1d058f08faea5306e629efd9 100644 (file)
--- a/src/utils/cplay.c
+++ b/src/utils/cplay.c
@@ -67,6 +67,7 @@
 #include <getopt.h>
 #include <sys/time.h>
 #include <config.h>
+#include <termios.h>
 #define __force
 #define __bitwise
 #define __user
@@ -75,7 +76,15 @@
 #include "tinycompress/tinymp3.h"
 #include "tinycompress/tinywave.h"
 
-static int verbose;
+enum {
+       DO_NOTHING = -1,
+       DO_PAUSE_PUSH,
+       DO_PAUSE_RELEASE
+};
+
+static int verbose, interactive;
+static bool is_paused = false;
+static long term_c_lflag = -1, stdin_flags = -1;
 static const unsigned int DEFAULT_CODEC_ID = SND_AUDIOCODEC_PCM;
 
 static const struct {
@@ -102,6 +111,99 @@ static const struct {
 };
 #define CPLAY_NUM_CODEC_IDS (sizeof(codec_ids) / sizeof(codec_ids[0]))
 
+static void init_stdin(void)
+{
+       struct termios term;
+       int ret;
+
+       if (!interactive)
+               return;
+
+       ret = tcgetattr(fileno(stdin), &term);
+       if (ret < 0) {
+               fprintf(stderr, "Unable to get terminal attributes.\n");
+               exit(EXIT_FAILURE);
+       }
+
+       /* save previous terminal flags */
+       term_c_lflag = term.c_lflag;
+
+       /* save previous stdin flags and add O_NONBLOCK*/
+       stdin_flags = fcntl(fileno(stdin), F_GETFL);
+       if (stdin_flags < 0 || fcntl(fileno(stdin), F_SETFL, stdin_flags|O_NONBLOCK) < 0)
+               fprintf(stderr, "stdin O_NONBLOCK flag setup failed\n");
+
+       /* prepare to enter noncanonical mode */
+       term.c_lflag &= ~ICANON;
+
+       ret = tcsetattr(fileno(stdin), TCSANOW, &term);
+       if (ret < 0) {
+               fprintf(stderr, "Unable to set terminal attributes.\n");
+               exit(EXIT_FAILURE);
+       }
+}
+
+static void done_stdin(void)
+{
+       struct termios term;
+       int ret;
+
+       if (!interactive)
+               return;
+
+       if (term_c_lflag == -1 || stdin_flags == -1)
+               return;
+
+       ret = tcgetattr(fileno(stdin), &term);
+       if (ret < 0) {
+               fprintf(stderr, "Unable to get terminal attributes.\n");
+               exit(EXIT_FAILURE);
+       }
+
+       /* restore previous terminal attributes */
+       term.c_lflag = term_c_lflag;
+
+       ret = tcsetattr(fileno(stdin), TCSANOW, &term);
+       if (ret < 0) {
+               fprintf(stderr, "Unable to set terminal attributes.\n");
+               exit(EXIT_FAILURE);
+       }
+
+       /* restore previous stdin attributes */
+       ret = fcntl(fileno(stdin), F_SETFL, stdin_flags);
+       if (ret < 0) {
+               fprintf(stderr, "Unable to set stdin attributes.\n");
+               exit(EXIT_FAILURE);
+       }
+}
+
+static int do_pause(void)
+{
+       unsigned char chr;
+
+       if (!interactive)
+               return DO_NOTHING;
+
+       while (read(fileno(stdin), &chr, 1) == 1) {
+               switch(chr) {
+                       case '\r':
+                       case ' ':
+                               if (is_paused) {
+                                       fprintf(stderr, "\r=== Resume ===\n");
+                                       return DO_PAUSE_RELEASE;
+                               } else {
+                                       fprintf(stderr, "\r=== Pause ===\n");
+                                       return DO_PAUSE_PUSH;
+                               }
+                               break;
+                       default:
+                               break;
+               }
+       }
+
+       return DO_NOTHING;
+}
+
 static void usage(void)
 {
        int i;
@@ -113,6 +215,7 @@ static void usage(void)
                "-b\tbuffer size\n"
                "-f\tfragments\n\n"
                "-v\tverbose mode\n"
+               "-i\tinteractive mode (press SPACE or ENTER for play/pause)\n"
                "-h\tPrints this help list\n\n"
                "Example:\n"
                "\tcplay -c 1 -d 2 test.mp3\n"
@@ -377,7 +480,7 @@ int main(int argc, char **argv)
                usage();
 
        verbose = 0;
-       while ((c = getopt(argc, argv, "hvb:f:c:d:I:")) != -1) {
+       while ((c = getopt(argc, argv, "hvb:f:c:d:I:i")) != -1) {
                switch (c) {
                case 'h':
                        usage();
@@ -416,6 +519,10 @@ int main(int argc, char **argv)
                case 'v':
                        verbose = 1;
                        break;
+               case 'i':
+                       fprintf(stderr, "Interactive mode: ON\n");
+                       interactive = 1;
+                       break;
                default:
                        exit(EXIT_FAILURE);
                }
@@ -564,6 +671,30 @@ void get_codec_iec(FILE *file, struct compr_config *config,
        codec->format = 0;
 }
 
+static int check_stdin(struct compress *compress)
+{
+       switch(do_pause()) {
+               case DO_PAUSE_PUSH:
+                       if (compress_pause(compress) != 0) {
+                               fprintf(stderr, "Pause ERROR\n");
+                               return -1;
+                       }
+                       is_paused = true;
+                       break;
+               case DO_PAUSE_RELEASE:
+                       if (compress_resume(compress) != 0) {
+                               fprintf(stderr, "Resume ERROR\n");
+                               return -1;
+                       }
+                       is_paused = false;
+                       break;
+               case DO_NOTHING:
+                       break;
+       }
+
+       return 0;
+}
+
 void play_samples(char *name, unsigned int card, unsigned int device,
                unsigned long buffer_size, unsigned int frag,
                unsigned long codec_id)
@@ -583,6 +714,8 @@ void play_samples(char *name, unsigned int card, unsigned int device,
                exit(EXIT_FAILURE);
        }
 
+       init_stdin();
+
        switch (codec_id) {
 #if ENABLE_PCM
        case SND_AUDIOCODEC_PCM:
@@ -655,7 +788,14 @@ void play_samples(char *name, unsigned int card, unsigned int device,
                printf("%s: You should hear audio NOW!!!\n", __func__);
 
        do {
-               num_read = fread(buffer, 1, size, file);
+               if (check_stdin(compress) != 0)
+                       goto BUF_EXIT;
+
+               if (!is_paused)
+                       num_read = fread(buffer, 1, size, file);
+               else
+                       num_read = 0;
+
                if (num_read > 0) {
                        wrote = compress_write(compress, buffer, num_read);
                        if (wrote < 0) {
@@ -672,7 +812,7 @@ void play_samples(char *name, unsigned int card, unsigned int device,
                                printf("%s: wrote %d\n", __func__, wrote);
                        }
                }
-       } while (num_read > 0);
+       } while (num_read > 0 || is_paused == true);
 
        if (verbose)
                printf("%s: exit success\n", __func__);
@@ -681,11 +821,13 @@ void play_samples(char *name, unsigned int card, unsigned int device,
        free(buffer);
        fclose(file);
        compress_close(compress);
+       done_stdin();
        return;
 BUF_EXIT:
        free(buffer);
 COMP_EXIT:
        compress_close(compress);
+       done_stdin();
 FILE_EXIT:
        fclose(file);
        if (verbose)