www/firefox: Fix for jitter when using the cubeb OSS audio backend.

Cherry-pick the following five changes from Mozilla's cubeb.git:
b690782c19728ee7a5675237b0b30249f4e1bf5e
8da61ef32d386ffd5f00f025578d4429523ca45b
1099a3007817fa34c1f91e4710ec046021147bed
5b0b7f6bf7c7a874abcb31de8dd386f147bab539
773f16b7ea308392c05be3e290163d1f636e6024

The need for this patch will eventually go away.

PR:		260061
Discussed with:	jbeich@ and khng@
Obtained from:	https://github.com/mozilla/cubeb.git
Approved by: pi (implicit)

2 files changed, 366 insertions, 1 deletions

diff --git a/www/firefox/Makefile b/www/firefox/Makefile
index 22153b974c4f..792ffad43941 100644
--- a/www/firefox/Makefile
+++ b/www/firefox/Makefile
@@ -2,7 +2,7 @@
 
 PORTNAME=	firefox
 DISTVERSION=	95.0
-PORTREVISION=	1
+PORTREVISION=	2
 PORTEPOCH=	2
 CATEGORIES=	www
 MASTER_SITES=	MOZILLA/${PORTNAME}/releases/${DISTVERSION}/source \
diff --git a/www/firefox/files/patch-media_libcubeb_src_cubeb__oss.c b/www/firefox/files/patch-media_libcubeb_src_cubeb__oss.c
new file mode 100644
index 000000000000..2449fa3d4195
--- /dev/null
+++ b/www/firefox/files/patch-media_libcubeb_src_cubeb__oss.c
@@ -0,0 +1,365 @@
+--- media/libcubeb/src/cubeb_oss.c.orig	2021-11-29 14:01:19 UTC
++++ media/libcubeb/src/cubeb_oss.c
+@@ -96,6 +96,7 @@ struct oss_stream {
+   oss_devnode_t name;
+   int fd;
+   void * buf;
++  unsigned int bufframes;
+ 
+   struct stream_info {
+     int channels;
+@@ -126,9 +127,6 @@ struct cubeb_stream {
+   cubeb_data_callback data_cb;
+   cubeb_state_callback state_cb;
+   uint64_t frames_written /* (m) */;
+-  unsigned int nfr; /* Number of frames allocated */
+-  unsigned int nfrags;
+-  unsigned int bufframes;
+ };
+ 
+ static char const *
+@@ -786,40 +784,72 @@ oss_put_play_frames(cubeb_stream * s, unsigned int nfr
+ }
+ 
+ static int
+-oss_wait_playfd_for_space(cubeb_stream * s)
++oss_wait_fds_for_space(cubeb_stream * s, long * nfrp)
+ {
+-  struct pollfd pfd;
++  audio_buf_info bi;
++  struct pollfd pfds[2];
++  long nfr, tnfr;
++  int i;
+ 
+-  pfd.events = POLLOUT | POLLHUP;
+-  pfd.revents = 0;
+-  pfd.fd = s->play.fd;
++  assert(s->play.fd != -1 || s->record.fd != -1);
++  pfds[0].events = POLLOUT | POLLHUP;
++  pfds[0].revents = 0;
++  pfds[0].fd = s->play.fd;
++  pfds[1].events = POLLIN | POLLHUP;
++  pfds[1].revents = 0;
++  pfds[1].fd = s->record.fd;
+ 
+-  if (poll(&pfd, 1, 2000) == -1) {
+-    return CUBEB_ERROR;
+-  }
++retry:
++  nfr = LONG_MAX;
+ 
+-  if (pfd.revents & POLLHUP) {
++  if (poll(pfds, 2, 1000) == -1) {
+     return CUBEB_ERROR;
+   }
+-  return 0;
+-}
+ 
+-static int
+-oss_wait_recfd_for_space(cubeb_stream * s)
+-{
+-  struct pollfd pfd;
+-
+-  pfd.events = POLLIN | POLLHUP;
+-  pfd.revents = 0;
+-  pfd.fd = s->record.fd;
+-
+-  if (poll(&pfd, 1, 2000) == -1) {
+-    return CUBEB_ERROR;
++  for (i = 0; i < 2; i++) {
++    if (pfds[i].revents & POLLHUP) {
++      return CUBEB_ERROR;
++    }
+   }
+ 
+-  if (pfd.revents & POLLHUP) {
+-    return CUBEB_ERROR;
++  if (s->play.fd != -1) {
++    if (ioctl(s->play.fd, SNDCTL_DSP_GETOSPACE, &bi) == -1) {
++      return CUBEB_STATE_ERROR;
++    }
++    tnfr = bi.bytes / s->play.frame_size;
++    if (tnfr <= 0) {
++      /* too little space - stop polling record, if any */
++      pfds[0].fd = s->play.fd;
++      pfds[1].fd = -1;
++      goto retry;
++    } else if (tnfr > (long)s->play.bufframes) {
++      /* too many frames available - limit */
++      tnfr = (long)s->play.bufframes;
++    }
++    if (nfr > tnfr) {
++      nfr = tnfr;
++    }
+   }
++  if (s->record.fd != -1) {
++    if (ioctl(s->record.fd, SNDCTL_DSP_GETISPACE, &bi) == -1) {
++      return CUBEB_STATE_ERROR;
++    }
++    tnfr = bi.bytes / s->record.frame_size;
++    if (tnfr <= 0) {
++      /* too little space - stop polling playback, if any */
++      pfds[0].fd = -1;
++      pfds[1].fd = s->record.fd;
++      goto retry;
++    } else if (tnfr > (long)s->record.bufframes) {
++      /* too many frames available - limit */
++      tnfr = (long)s->record.bufframes;
++    }
++    if (nfr > tnfr) {
++      nfr = tnfr;
++    }
++  }
++
++  *nfrp = nfr;
+   return 0;
+ }
+ 
+@@ -840,7 +870,7 @@ oss_audio_loop(cubeb_stream * s, cubeb_state * new_sta
+     }
+ 
+     trig |= PCM_ENABLE_INPUT;
+-    memset(s->record.buf, 0, s->bufframes * s->record.frame_size);
++    memset(s->record.buf, 0, s->record.bufframes * s->record.frame_size);
+ 
+     if (ioctl(s->record.fd, SNDCTL_DSP_SETTRIGGER, &trig) == -1) {
+       LOG("Error %d occured when setting trigger on record fd", errno);
+@@ -877,6 +907,7 @@ oss_audio_loop(cubeb_stream * s, cubeb_state * new_sta
+           oss_linear32_to_float(s->record.buf, s->record.info.channels * nfr);
+         }
+       }
++
+       got = s->data_cb(s, s->user_ptr, s->record.buf, s->play.buf, nfr);
+       if (got == CUBEB_ERROR) {
+         state = CUBEB_STATE_ERROR;
+@@ -920,45 +951,10 @@ oss_audio_loop(cubeb_stream * s, cubeb_state * new_sta
+       }
+     }
+ 
+-    nfr = s->bufframes;
+-
+-    if (record_on) {
+-      long mfr;
+-
+-      if (oss_wait_recfd_for_space(s) != 0) {
+-        state = CUBEB_STATE_ERROR;
+-        goto breakdown;
+-      }
+-
+-      audio_buf_info bi;
+-      if (ioctl(s->record.fd, SNDCTL_DSP_GETISPACE, &bi) == -1) {
+-        state = CUBEB_STATE_ERROR;
+-        goto breakdown;
+-      }
+-
+-      mfr = (bi.fragsize * bi.fragments) / s->record.frame_size;
+-      if (nfr > mfr)
+-        nfr = mfr;
++    if (oss_wait_fds_for_space(s, &nfr) != 0) {
++      state = CUBEB_STATE_ERROR;
++      goto breakdown;
+     }
+-
+-    if (play_on) {
+-      long mfr;
+-
+-      if (oss_wait_playfd_for_space(s) != 0) {
+-        state = CUBEB_STATE_ERROR;
+-        goto breakdown;
+-      }
+-
+-      audio_buf_info bi;
+-      if (ioctl(s->play.fd, SNDCTL_DSP_GETOSPACE, &bi) == -1) {
+-        state = CUBEB_STATE_ERROR;
+-        goto breakdown;
+-      }
+-
+-      mfr = (bi.fragsize * bi.fragments) / s->play.frame_size;
+-      if (nfr > mfr)
+-        nfr = mfr;
+-    }
+   }
+ 
+   return 1;
+@@ -1015,9 +1011,10 @@ static inline int
+ oss_calc_frag_shift(unsigned int frames, unsigned int frame_size)
+ {
+   int n = 4;
+-  int blksize = (frames * frame_size + OSS_NFRAGS - 1) / OSS_NFRAGS;
+-  while ((1 << n) < blksize)
++  int blksize = frames * frame_size;
++  while ((1 << n) < blksize) {
+     n++;
++  }
+   return n;
+ }
+ 
+@@ -1037,7 +1034,6 @@ oss_stream_init(cubeb * context, cubeb_stream ** strea
+                 cubeb_state_callback state_callback, void * user_ptr)
+ {
+   int ret = CUBEB_OK;
+-  unsigned int playnfr = 0, recnfr = 0;
+   cubeb_stream * s = NULL;
+   const char * defdsp;
+ 
+@@ -1051,7 +1047,6 @@ oss_stream_init(cubeb * context, cubeb_stream ** strea
+   }
+   s->state = CUBEB_STATE_STOPPED;
+   s->record.fd = s->play.fd = -1;
+-  s->nfr = latency_frames;
+   if (input_device != NULL) {
+     strlcpy(s->record.name, input_device, sizeof(s->record.name));
+   } else {
+@@ -1064,6 +1059,8 @@ oss_stream_init(cubeb * context, cubeb_stream ** strea
+   }
+   if (input_stream_params != NULL) {
+     unsigned int nb_channels;
++    uint32_t minframes;
++
+     if (input_stream_params->prefs & CUBEB_STREAM_PREF_LOOPBACK) {
+       LOG("Loopback not supported");
+       ret = CUBEB_ERROR_NOT_SUPPORTED;
+@@ -1077,13 +1074,11 @@ oss_stream_init(cubeb * context, cubeb_stream ** strea
+       ret = CUBEB_ERROR_INVALID_PARAMETER;
+       goto error;
+     }
+-    if (s->record.fd == -1) {
+-      if ((s->record.fd = open(s->record.name, O_RDONLY)) == -1) {
+-        LOG("Audio device \"%s\" could not be opened as read-only",
+-            s->record.name);
+-        ret = CUBEB_ERROR_DEVICE_UNAVAILABLE;
+-        goto error;
+-      }
++    if ((s->record.fd = open(s->record.name, O_RDONLY)) == -1) {
++      LOG("Audio device \"%s\" could not be opened as read-only",
++          s->record.name);
++      ret = CUBEB_ERROR_DEVICE_UNAVAILABLE;
++      goto error;
+     }
+     if ((ret = oss_copy_params(s->record.fd, s, input_stream_params,
+                                &s->record.info)) != CUBEB_OK) {
+@@ -1094,11 +1089,17 @@ oss_stream_init(cubeb * context, cubeb_stream ** strea
+         (input_stream_params->format == CUBEB_SAMPLE_FLOAT32NE);
+     s->record.frame_size =
+         s->record.info.channels * (s->record.info.precision / 8);
+-    recnfr = (1 << oss_calc_frag_shift(s->nfr, s->record.frame_size)) /
+-             s->record.frame_size;
++    s->record.bufframes = latency_frames;
++
++    oss_get_min_latency(context, *input_stream_params, &minframes);
++    if (s->record.bufframes < minframes) {
++      s->record.bufframes = minframes;
++    }
+   }
+   if (output_stream_params != NULL) {
+     unsigned int nb_channels;
++    uint32_t minframes;
++
+     if (output_stream_params->prefs & CUBEB_STREAM_PREF_LOOPBACK) {
+       LOG("Loopback not supported");
+       ret = CUBEB_ERROR_NOT_SUPPORTED;
+@@ -1113,13 +1114,11 @@ oss_stream_init(cubeb * context, cubeb_stream ** strea
+       ret = CUBEB_ERROR_INVALID_PARAMETER;
+       goto error;
+     }
+-    if (s->play.fd == -1) {
+-      if ((s->play.fd = open(s->play.name, O_WRONLY)) == -1) {
+-        LOG("Audio device \"%s\" could not be opened as write-only",
+-            s->play.name);
+-        ret = CUBEB_ERROR_DEVICE_UNAVAILABLE;
+-        goto error;
+-      }
++    if ((s->play.fd = open(s->play.name, O_WRONLY)) == -1) {
++      LOG("Audio device \"%s\" could not be opened as write-only",
++          s->play.name);
++      ret = CUBEB_ERROR_DEVICE_UNAVAILABLE;
++      goto error;
+     }
+     if ((ret = oss_copy_params(s->play.fd, s, output_stream_params,
+                                &s->play.info)) != CUBEB_OK) {
+@@ -1128,19 +1127,16 @@ oss_stream_init(cubeb * context, cubeb_stream ** strea
+     }
+     s->play.floating = (output_stream_params->format == CUBEB_SAMPLE_FLOAT32NE);
+     s->play.frame_size = s->play.info.channels * (s->play.info.precision / 8);
+-    playnfr = (1 << oss_calc_frag_shift(s->nfr, s->play.frame_size)) /
+-              s->play.frame_size;
++    s->play.bufframes = latency_frames;
++
++    oss_get_min_latency(context, *output_stream_params, &minframes);
++    if (s->play.bufframes < minframes) {
++      s->play.bufframes = minframes;
++    }
+   }
+-  /*
+-   * Use the largest nframes among playing and recording streams to set OSS
+-   * buffer size. After that, use the smallest allocated nframes among both
+-   * direction to allocate our temporary buffers.
+-   */
+-  s->nfr = (playnfr > recnfr) ? playnfr : recnfr;
+-  s->nfrags = OSS_NFRAGS;
+   if (s->play.fd != -1) {
+-    int frag =
+-        oss_get_frag_params(oss_calc_frag_shift(s->nfr, s->play.frame_size));
++    int frag = oss_get_frag_params(
++        oss_calc_frag_shift(s->play.bufframes, s->play.frame_size));
+     if (ioctl(s->play.fd, SNDCTL_DSP_SETFRAGMENT, &frag))
+       LOG("Failed to set play fd with SNDCTL_DSP_SETFRAGMENT. frag: 0x%x",
+           frag);
+@@ -1148,13 +1144,17 @@ oss_stream_init(cubeb * context, cubeb_stream ** strea
+     if (ioctl(s->play.fd, SNDCTL_DSP_GETOSPACE, &bi))
+       LOG("Failed to get play fd's buffer info.");
+     else {
+-      if (bi.fragsize / s->play.frame_size < s->nfr)
+-        s->nfr = bi.fragsize / s->play.frame_size;
++      s->play.bufframes = (bi.fragsize * bi.fragstotal) / s->play.frame_size;
+     }
++
++    int lw = s->play.frame_size;
++    if (ioctl(s->play.fd, SNDCTL_DSP_LOW_WATER, &lw))
++      LOG("Audio device \"%s\" (play) could not set trigger threshold",
++          s->play.name);
+   }
+   if (s->record.fd != -1) {
+-    int frag =
+-        oss_get_frag_params(oss_calc_frag_shift(s->nfr, s->record.frame_size));
++    int frag = oss_get_frag_params(
++        oss_calc_frag_shift(s->record.bufframes, s->record.frame_size));
+     if (ioctl(s->record.fd, SNDCTL_DSP_SETFRAGMENT, &frag))
+       LOG("Failed to set record fd with SNDCTL_DSP_SETFRAGMENT. frag: 0x%x",
+           frag);
+@@ -1162,11 +1162,15 @@ oss_stream_init(cubeb * context, cubeb_stream ** strea
+     if (ioctl(s->record.fd, SNDCTL_DSP_GETISPACE, &bi))
+       LOG("Failed to get record fd's buffer info.");
+     else {
+-      if (bi.fragsize / s->record.frame_size < s->nfr)
+-        s->nfr = bi.fragsize / s->record.frame_size;
++      s->record.bufframes =
++          (bi.fragsize * bi.fragstotal) / s->record.frame_size;
+     }
++
++    int lw = s->record.frame_size;
++    if (ioctl(s->record.fd, SNDCTL_DSP_LOW_WATER, &lw))
++      LOG("Audio device \"%s\" (record) could not set trigger threshold",
++          s->record.name);
+   }
+-  s->bufframes = s->nfr * s->nfrags;
+   s->context = context;
+   s->volume = 1.0;
+   s->state_cb = state_callback;
+@@ -1188,13 +1192,14 @@ oss_stream_init(cubeb * context, cubeb_stream ** strea
+   s->doorbell = false;
+ 
+   if (s->play.fd != -1) {
+-    if ((s->play.buf = calloc(s->bufframes, s->play.frame_size)) == NULL) {
++    if ((s->play.buf = calloc(s->play.bufframes, s->play.frame_size)) == NULL) {
+       ret = CUBEB_ERROR;
+       goto error;
+     }
+   }
+   if (s->record.fd != -1) {
+-    if ((s->record.buf = calloc(s->bufframes, s->record.frame_size)) == NULL) {
++    if ((s->record.buf = calloc(s->record.bufframes, s->record.frame_size)) ==
++        NULL) {
+       ret = CUBEB_ERROR;
+       goto error;
+     }