avformat/libopenmpt: fix seeking weirdness

- proper pts for packets. leaving it blank leaves it up for guessing,
  but the guess doesn't take seeking into account, causing weirdness.

- clamp to 0 when seeking to negative ts. libopenmpt docs are unclear on
  this but not doing this causes an immediate EOF when seeking backwards
  to the beginning in mpv.

- only set song duration and packet pts when they are non-negative and
  in int64 range. NaNs count as out of range. this isn't a fix for any
  specific issue but might be helpful still, and shouldn't break
  anything.

1 files changed, 9 insertions, 1 deletions

diff --git a/libavformat/libopenmpt.c b/libavformat/libopenmpt.c
index dee975c9c2..46af4bff22 100644
--- a/libavformat/libopenmpt.c
+++ b/libavformat/libopenmpt.c
@@ -148,7 +148,8 @@ static int read_header_openmpt(AVFormatContext *s)
     if (!st)
         return AVERROR(ENOMEM);
     avpriv_set_pts_info(st, 64, 1, AV_TIME_BASE);
-    st->duration = llrint(openmpt->duration*AV_TIME_BASE);
+    if (openmpt->duration >= 0 && openmpt->duration < ((double)INT64_MAX + 1) / AV_TIME_BASE)
+        st->duration = llrint(openmpt->duration*AV_TIME_BASE);
 
     st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
     st->codecpar->codec_id    = AV_NE(AV_CODEC_ID_PCM_F32BE, AV_CODEC_ID_PCM_F32LE);
@@ -171,6 +172,8 @@ static int read_packet_openmpt(AVFormatContext *s, AVPacket *pkt)
     if ((ret = av_new_packet(pkt, AUDIO_PKT_SIZE)) < 0)
         return ret;
 
+    double pos = openmpt_module_get_position_seconds(openmpt->module);
+
     switch (openmpt->ch_layout.nb_channels) {
     case 1:
         ret = openmpt_module_read_float_mono(openmpt->module, openmpt->sample_rate,
@@ -196,6 +199,9 @@ static int read_packet_openmpt(AVFormatContext *s, AVPacket *pkt)
 
     pkt->size = ret * (openmpt->ch_layout.nb_channels * 4);
 
+    if (pos >= 0 && pos < ((double)INT64_MAX + 1) / AV_TIME_BASE)
+        pkt->pts = llrint(pos * AV_TIME_BASE);
+
     return 0;
 }
 
@@ -212,6 +218,8 @@ static int read_close_openmpt(AVFormatContext *s)
 static int read_seek_openmpt(AVFormatContext *s, int stream_idx, int64_t ts, int flags)
 {
     OpenMPTContext *openmpt = s->priv_data;
+    if (ts < 0)
+        ts = 0;
     openmpt_module_set_position_seconds(openmpt->module, (double)ts/AV_TIME_BASE);
     return 0;
 }