Re: [alsa-devel] Aplay Fails When Reading From stdin

On 5/4/2018 11:51 PM, Takashi Iwai wrote:

On Fri, 04 May 2018 21:57:35 +0200, Jay Foster wrote:

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On 5/4/2018 12:47 PM, Takashi Iwai wrote:

...

On Fri, 04 May 2018 19:51:05 +0200, Jay Foster wrote:

...

I recently updated may alsa from 1.1.4.1 to 1.1.6. I now noticed that aplay does not work properly (the same as 1.1.4.1) when reading the sound file data from stdin. This might have something to do with the recent change with reading the sound file header.

With the previous version of aplay, aplay would report:

Playing WAVE 'stdin' : Signed 16 bit Little Endian, Rate 22050 Hz, Mono

With 1.1.6, aplay reports:

Playing raw data 'stdin' : Unsigned 8 bit, Rate 8000 Hz, Mono

This results in static/noise output. If I explicitly add the '-f S16_LE -r 22050' options to aplay, then it does play correctly.

Is this a known bug and is there a fix?

It works fine on my system.

% aplay test.wav Playing WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo

% aplay < ~/test/test.wav Playing WAVE 'stdin' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo

% aplay --version aplay: version 1.1.6 by Jaroslav Kysela perex@perex.cz

Takashi

Well, it does not work for me:

cat bird-calls.wav | /usr/bin/aplay -Dplughw:0 -- Playing raw data 'stdin' : Unsigned 8 bit, Rate 8000 Hz, Mono ^CAborted by signal Interrupt... aplay: pcm_write:2051: write error: Interrupted system call

aplay -Dplughw:0 bird-calls.wav Playing WAVE 'bird-calls.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo

Looks like aplay may now have problems reading from stdin if stdin is a pipe.

OK, now I see it. It's in the safety check of file stat. The fix patch is below.

thanks,

Takashi

---

diff --git a/aplay/aplay.c b/aplay/aplay.c index bbd7fffa04fc..2a851a73ba6e 100644 --- a/aplay/aplay.c +++ b/aplay/aplay.c @@ -2808,7 +2808,7 @@ static void playback_go(int fd, size_t loaded, off64_t count, int rtype, char *n snd_pcm_nonblock(handle, nonblock); }

-static int read_header(int *loaded, int header_size) +static int read_header(int *loaded, int header_size, int is_stdin) { int ret; struct stat buf; @@ -2821,7 +2821,7 @@ static int read_header(int *loaded, int header_size)

/* don't be adventurous, get out if file size is smaller than * requested header size */

• if (buf.st_size < header_size)

• if (!is_stdin && buf.st_size < header_size) return -1;

  if (*loaded < header_size) {

@@ -2836,9 +2836,9 @@ static int read_header(int *loaded, int header_size) return 0; }

-static int playback_au(char *name, int *loaded) +static int playback_au(char *name, int *loaded, int is_stdin) {

• if (read_header(loaded, sizeof(AuHeader)) < 0)

• if (read_header(loaded, sizeof(AuHeader), is_stdin) < 0) return -1;

  if (test_au(fd, audiobuf) < 0)

@@ -2851,11 +2851,11 @@ static int playback_au(char *name, int *loaded) return 0; }

-static int playback_voc(char *name, int *loaded) +static int playback_voc(char *name, int *loaded, int is_stdin) { int ofs;

• if (read_header(loaded, sizeof(VocHeader)) < 0)

• if (read_header(loaded, sizeof(VocHeader), is_stdin) < 0) return -1;

  if ((ofs = test_vocfile(audiobuf)) < 0)

@@ -2867,11 +2867,11 @@ static int playback_voc(char *name, int *loaded) return 0; }

-static int playback_wave(char *name, int *loaded) +static int playback_wave(char *name, int *loaded, int is_stdin) { ssize_t dtawave;

• if (read_header(loaded, sizeof(WaveHeader)) < 0)

• if (read_header(loaded, sizeof(WaveHeader), is_stdin) < 0) return -1;

  if ((dtawave = test_wavefile(fd, audiobuf, *loaded)) < 0)

@@ -2883,7 +2883,7 @@ static int playback_wave(char *name, int *loaded) return 0; }

-static int playback_raw(char *name, int *loaded) +static int playback_raw(char *name, int *loaded, int is_stdin) { init_raw_data(); pbrec_count = calc_count(); @@ -2899,13 +2899,16 @@ static int playback_raw(char *name, int *loaded) static void playback(char *name) { int loaded = 0;

• int is_stdin;

  pbrec_count = LLONG_MAX; fdcount = 0; if (!name || !strcmp(name, "-")) {

• is_stdin = 1;
  

  fd = fileno(stdin); name = "stdin"; } else {

• is_stdin = 0;
  

  init_stdin(); if ((fd = open(name, O_RDONLY, 0)) == -1) { perror(name);

@@ -2915,23 +2918,23 @@ static void playback(char *name)

switch(file_type) { case FORMAT_AU:

• playback_au(name, &loaded);
  

• playback_au(name, &loaded, is_stdin);
  

  break; case FORMAT_VOC:

• playback_voc(name, &loaded);
  

• playback_voc(name, &loaded, is_stdin);
  

  break; case FORMAT_WAVE:

• playback_wave(name, &loaded);
  

• playback_wave(name, &loaded, is_stdin);
  

  break; case FORMAT_RAW:

• playback_raw(name, &loaded);
  

• playback_raw(name, &loaded, is_stdin);
  

  break; default: /* parse the file header */

• if (playback_au(name, &loaded) < 0 &&
  

•     playback_voc(name, &loaded) < 0 &&
  

•     playback_wave(name, &loaded) < 0)
  

• 	playback_raw(name, &loaded); /* should be raw data */
  

• if (playback_au(name, &loaded, is_stdin) < 0 &&
  

•     playback_voc(name, &loaded, is_stdin) < 0 &&
  

•     playback_wave(name, &loaded, is_stdin) < 0)
  

• 	playback_raw(name, &loaded, is_stdin); /* should be raw data */
  

  break; }

Thanks.  That works. Jay