Attachment 132024 Details for Bug 81075 – "Fix" integer overflow and negative latency issues and add comments (seems to actually make things worse)

[patch] "Fix" integer overflow and negative latency issues and add comments (seems to actually make things worse)

0001-wip-fix-issues-in-pa_simple_get_latency.patch (text/plain), 2.47 KB, created by Tanu Kaskinen on 2017-06-17 16:42:55 UTC

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Creator: Tanu Kaskinen

Created: 2017-06-17 16:42:55 UTC

Size: 2.47 KB

patch

obsolete

>From 4d2dbbf43ea571b678338c66a8ed13853c1e20b2 Mon Sep 17 00:00:00 2001
>From: Tanu Kaskinen <tanuk@iki.fi>
>Date: Sat, 17 Jun 2017 18:51:47 +0300
>Subject: [PATCH] wip: fix issues in pa_simple_get_latency()
>
>This seems to make things worse for some reason...
>---
> src/pulse/simple.c | 40 ++++++++++++++++++++++++++++------------
> 1 file changed, 28 insertions(+), 12 deletions(-)
>
>diff --git a/src/pulse/simple.c b/src/pulse/simple.c
>index c8e89b09b..7b66f62d7 100644
>--- a/src/pulse/simple.c
>+++ b/src/pulse/simple.c
>@@ -463,18 +463,34 @@ pa_usec_t pa_simple_get_latency(pa_simple *p, int *rerror) {
>         CHECK_DEAD_GOTO(p, rerror, unlock_and_fail);
> 
>         if (pa_stream_get_latency(p->stream, &t, &negative) >= 0) {
>-            pa_usec_t extra = 0;
>-
>-            if (p->direction == PA_STREAM_RECORD)
>-                extra = -pa_bytes_to_usec(p->read_index, pa_stream_get_sample_spec(p->stream));
>-
>-            if (negative) {
>-                if (extra > t)
>-                    t = extra - t;
>-                else
>-                    t = 0;
>-            } else
>-                t += extra;
>+            if (p->direction == PA_STREAM_RECORD) {
>+                pa_usec_t already_read;
>+
>+                /* pa_simple_read() calls pa_stream_peek() to get the next
>+                 * chunk of audio. If the next chunk is larger than what the
>+                 * pa_simple_read() caller wanted, the leftover data is stored
>+                 * in p->read_data until pa_simple_read() is called again.
>+                 * pa_stream_drop() won't be called until the whole chunk has
>+                 * been consumed, which means that pa_stream_get_latency() will
>+                 * return too large values, because the whole size of the
>+                 * partially read chunk is included in the latency. Therefore,
>+                 * we need to substract the already-read amount from the
>+                 * latency. */
>+                already_read = pa_bytes_to_usec(p->read_index, pa_stream_get_sample_spec(p->stream));
>+
>+                if (!negative) {
>+                    if (t > already_read)
>+                        t -= already_read;
>+                    else
>+                        t = 0;
>+                }
>+            }
>+
>+            /* We don't have a way to report negative latencies from
>+             * pa_simple_get_latency(). If the latency is negative, let's
>+             * report zero. */
>+            if (negative)
>+                t = 0;
> 
>             break;
>         }
>-- 
>2.11.0
>

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Attachments on bug 81075: 102473 | 102705 | 102706 | 102707 | 102708 | 102709 | 131661 | 131662 | 131663 | 131664 | 131665 | 132024

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