From 34f2970157c3100ea4bfe66fef08d4ca74746ca3 Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Sat, 25 Oct 2014 17:56:29 +0200
Subject: tv: remove some differences between immediate/normal mode

The immediate mode (which is the default) uses a tiny ringbuffer and
doesn't grab timestamps. This leads to quite bad behavior due to the
fact that there's an additional buffer between playloop and TV code (the
demuxer thread, which doesn't exist in MPlayer).

Always grab the timestamps and use a decently-sized buffer. I still have
no clue what I'm doing, and hacked it until it appeared to work. Report
regressions if you experience any.
---
 stream/tvi_v4l2.c | 61 +++++++++++++++++++++----------------------------------
 1 file changed, 23 insertions(+), 38 deletions(-)

diff --git a/stream/tvi_v4l2.c b/stream/tvi_v4l2.c
index 8738088a0a..eac99ba042 100644
--- a/stream/tvi_v4l2.c
+++ b/stream/tvi_v4l2.c
@@ -1243,12 +1243,7 @@ static int start(priv_t *priv)
     init_audio(priv);
     if (priv->tv_param->audio && !priv->audio_initialized) return 0;
 
-    /* we need this to size the audio buffer properly */
-    if (priv->immediate_mode) {
-        priv->video_buffer_size_max = 2;
-    } else {
-        priv->video_buffer_size_max = get_capture_buffer_size(priv);
-    }
+    priv->video_buffer_size_max = get_capture_buffer_size(priv);
 
     if (priv->tv_param->audio) {
         setup_audio_buffer_sizes(priv);
@@ -1319,11 +1314,7 @@ static int start(priv_t *priv)
     priv->video_cnt = 0;
 
     /* request buffers */
-    if (priv->immediate_mode) {
-        request.count = 2;
-    } else {
-        request.count = BUFFER_COUNT;
-    }
+    request.count = BUFFER_COUNT;
 
     request.type  = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     request.memory = V4L2_MEMORY_MMAP;
@@ -1435,12 +1426,10 @@ static void *video_grabber(void *data)
     {
         int ret;
 
-        if (priv->immediate_mode) {
-            while (priv->video_cnt == priv->video_buffer_size_max) {
-                usleep(10000);
-                if (priv->shutdown) {
-                    return NULL;
-                }
+        while (priv->video_cnt == priv->video_buffer_size_max) {
+            usleep(10000);
+            if (priv->shutdown) {
+                return NULL;
             }
         }
 
@@ -1513,19 +1502,17 @@ static void *video_grabber(void *data)
         interval = priv->curr_frame - priv->first_frame;
         delta = interval - prev_interval;
 
-        if (!priv->immediate_mode) {
-            // interpolate the skew in time
-            if (priv->tv_param->audio) pthread_mutex_lock(&priv->skew_mutex);
-            xskew = priv->audio_skew + (interval - priv->audio_skew_measure_time)*priv->audio_skew_factor;
-            if (priv->tv_param->audio) pthread_mutex_unlock(&priv->skew_mutex);
-             // correct extreme skew changes to avoid (especially) moving backwards in time
-            if (xskew - prev_skew > delta*MAX_SKEW_DELTA) {
-                skew = prev_skew + delta*MAX_SKEW_DELTA;
-            } else if (xskew - prev_skew < -delta*MAX_SKEW_DELTA) {
-                skew = prev_skew - delta*MAX_SKEW_DELTA;
-            } else {
-                skew = xskew;
-            }
+        // interpolate the skew in time
+        if (priv->tv_param->audio) pthread_mutex_lock(&priv->skew_mutex);
+        xskew = priv->audio_skew + (interval - priv->audio_skew_measure_time)*priv->audio_skew_factor;
+        if (priv->tv_param->audio) pthread_mutex_unlock(&priv->skew_mutex);
+            // correct extreme skew changes to avoid (especially) moving backwards in time
+        if (xskew - prev_skew > delta*MAX_SKEW_DELTA) {
+            skew = prev_skew + delta*MAX_SKEW_DELTA;
+        } else if (xskew - prev_skew < -delta*MAX_SKEW_DELTA) {
+            skew = prev_skew - delta*MAX_SKEW_DELTA;
+        } else {
+            skew = xskew;
         }
 
         MP_TRACE(priv, "\nfps = %f, interval = %f, a_skew = %f, corr_skew = %f\n",
@@ -1553,17 +1540,15 @@ static void *video_grabber(void *data)
         pthread_mutex_unlock(&priv->video_buffer_mutex);
 
         if (priv->video_cnt == priv->video_buffer_size_current) {
-            if (!priv->immediate_mode) {
-                MP_ERR(priv, "\nvideo buffer full - dropping frame\n");
-                if (priv->audio_insert_null_samples) {
-                    pthread_mutex_lock(&priv->audio_mutex);
-                    priv->dropped_frames_timeshift += delta;
-                    pthread_mutex_unlock(&priv->audio_mutex);
-                }
+            MP_ERR(priv, "\nvideo buffer full - dropping frame\n");
+            if (!priv->immediate_mode || priv->audio_insert_null_samples) {
+                pthread_mutex_lock(&priv->audio_mutex);
+                priv->dropped_frames_timeshift += delta;
+                pthread_mutex_unlock(&priv->audio_mutex);
             }
         } else {
             if (priv->immediate_mode) {
-                priv->video_ringbuffer[priv->video_tail].timestamp = -1;
+                priv->video_ringbuffer[priv->video_tail].timestamp = interval - skew;
             } else {
                 // compensate for audio skew
                 // negative skew => there are more audio samples, increase interval
-- 
cgit v1.2.3