stream: use native libavformat reconnection feature

Remove our own hacky reconnection code, and use libavformat's feature for
that. It's disabled by default, and until recently it did not work too
well. This has been fixed in recent ffmpeg git master[1], so there's no reason
to keep our own code.

[1] FFmpeg/FFmpeg@8a108bdea06fac43af9f44b6d2538f357451167a

We set "reconnect_delay_max" to 7, which limits the maximum time it
waits. Since libavformat doubles the wait time on each reconnect attempt
(starting with 1), and stops trying to reconnect once the wait time is
over the reconnect_delay_max value, this allows for 4 reconnection
attempts which should add to 11 seconds maximum wait time. The default
is 120, which seems too high for normal playback use.

(The user can still override these parameters with --stream-lavf-o.)

4 files changed, 3 insertions, 64 deletions

diff --git a/stream/cache.c b/stream/cache.c
index d91ae73b05..10e1bd7ce7 100644
--- a/stream/cache.c
+++ b/stream/cache.c
@@ -504,7 +504,6 @@ static bool control_needs_flush(int stream_ctrl)
     case STREAM_CTRL_AVSEEK:
     case STREAM_CTRL_SET_ANGLE:
     case STREAM_CTRL_SET_CURRENT_TITLE:
-    case STREAM_CTRL_RECONNECT:
     case STREAM_CTRL_DVB_SET_CHANNEL:
     case STREAM_CTRL_DVB_SET_CHANNEL_NAME:
     case STREAM_CTRL_DVB_STEP_CHANNEL:
diff --git a/stream/stream.c b/stream/stream.c
index dba30d5df2..255e583de2 100644
--- a/stream/stream.c
+++ b/stream/stream.c
@@ -336,32 +336,6 @@ stream_t *open_output_stream(const char *filename, struct mpv_global *global)
     return stream_create(filename, STREAM_WRITE, NULL, global);
 }
 
-static bool stream_reconnect(stream_t *s)
-{
-    if (!s->streaming || s->caching || !s->seekable || !s->cancel)
-        return false;
-
-    double sleep_secs = 0;
-    for (int retry = 0; retry < 6; retry++) {
-        if (mp_cancel_wait(s->cancel, sleep_secs))
-            break;
-
-        int r = stream_control(s, STREAM_CTRL_RECONNECT, NULL);
-        if (r == STREAM_UNSUPPORTED)
-            break;
-        if (r == STREAM_OK) {
-            MP_WARN(s, "Reconnected successfully.\n");
-            return true;
-        }
-
-        MP_WARN(s, "Connection lost! Attempting to reconnect (%d)...\n", retry + 1);
-
-        sleep_secs = MPMAX(sleep_secs, 0.1);
-        sleep_secs = MPMIN(sleep_secs * 4, 10.0);
-    }
-    return false;
-}
-
 // Read function bypassing the local stream buffer. This will not write into
 // s->buffer, but into buf[0..len] instead.
 // Returns 0 on error or EOF, and length of bytes read on success.
@@ -374,15 +348,6 @@ static int stream_read_unbuffered(stream_t *s, void *buf, int len)
     if (s->fill_buffer && !mp_cancel_test(s->cancel))
         res = s->fill_buffer(s, buf, len);
     if (res <= 0) {
-        // just in case this is an error e.g. due to network
-        // timeout reset and retry
-        // do not retry if this looks like proper eof
-        int64_t size = stream_get_size(s);
-        if (!s->eof && s->pos != size && stream_reconnect(s)) {
-            s->eof = 1; // make sure EOF is set to ensure no endless recursion
-            return stream_read_unbuffered(s, buf, len);
-        }
-
         s->eof = 1;
         return 0;
     }
diff --git a/stream/stream.h b/stream/stream.h
index ba2b0ca2af..3ce74ecd15 100644
--- a/stream/stream.h
+++ b/stream/stream.h
@@ -64,7 +64,6 @@ enum stream_ctrl {
     STREAM_CTRL_GET_BASE_FILENAME,
 
     // Certain network protocols
-    STREAM_CTRL_RECONNECT,
     STREAM_CTRL_AVSEEK,
     STREAM_CTRL_HAS_AVSEEK,
     STREAM_CTRL_GET_METADATA,
diff --git a/stream/stream_lavf.c b/stream/stream_lavf.c
index 2230247f28..82d9b3a392 100644
--- a/stream/stream_lavf.c
+++ b/stream/stream_lavf.c
@@ -77,8 +77,6 @@ static struct mp_tags *read_icy(stream_t *stream);
 static int fill_buffer(stream_t *s, char *buffer, int max_len)
 {
     AVIOContext *avio = s->priv;
-    if (!avio)
-        return -1;
 #if LIBAVFORMAT_VERSION_MICRO >= 100 && LIBAVFORMAT_VERSION_INT >= AV_VERSION_INT(57, 81, 100)
     int r = avio_read_partial(avio, buffer, max_len);
 #else
@@ -90,8 +88,6 @@ static int fill_buffer(stream_t *s, char *buffer, int max_len)
 static int write_buffer(stream_t *s, char *buffer, int len)
 {
     AVIOContext *avio = s->priv;
-    if (!avio)
-        return -1;
     avio_write(avio, buffer, len);
     avio_flush(avio);
     if (avio->error)
@@ -102,8 +98,6 @@ static int write_buffer(stream_t *s, char *buffer, int len)
 static int seek(stream_t *s, int64_t newpos)
 {
     AVIOContext *avio = s->priv;
-    if (!avio)
-        return -1;
     if (avio_seek(avio, newpos, SEEK_SET) < 0) {
         return 0;
     }
@@ -125,8 +119,6 @@ static void close_f(stream_t *stream)
 static int control(stream_t *s, int cmd, void *arg)
 {
     AVIOContext *avio = s->priv;
-    if (!avio && cmd != STREAM_CTRL_RECONNECT)
-        return -1;
     int64_t size;
     switch(cmd) {
     case STREAM_CTRL_GET_SIZE:
@@ -175,25 +167,6 @@ static int control(stream_t *s, int cmd, void *arg)
             break;
         return 1;
     }
-    case STREAM_CTRL_RECONNECT: {
-        if (avio && avio->write_flag)
-            break; // don't bother with this
-        // avio supports reconneting for http (as private avio option), but it
-        // seems somewhat broken and drops part of the stream if the first
-        // reconnect does not work. emulate it.
-        close_f(s);
-        s->priv = NULL;
-        int res = open_f(s);
-        if (res == STREAM_OK) {
-            if (!seek(s, s->pos)) {
-                MP_WARN(s, "Reconnecting failed.\n");
-                close_f(s);
-                s->priv = NULL;
-                return STREAM_UNSUPPORTED;
-            }
-        }
-        return res;
-    }
     }
     return STREAM_UNSUPPORTED;
 }
@@ -313,6 +286,9 @@ static int open_f(stream_t *stream)
         filename = talloc_asprintf(temp, "mmsh://%.*s", BSTR_P(b_filename));
     }
 
+    av_dict_set(&dict, "reconnect", "1", 0);
+    av_dict_set(&dict, "reconnect_delay_max", "7", 0);
+
     mp_setup_av_network_options(&dict, stream->global, stream->log);
 
     AVIOInterruptCB cb = {