[FFmpeg-cvslog] format/imfdec: improve error handling when selecting tracks for playback

[Pierre-Anthony Lemieux]

ffmpeg | branch: master | Pierre-Anthony Lemieux <pal at palemieux.com> | Mon Sep 19 08:26:18 2022 -0700| [0e402ebf487075727187c78f85908a492eed3e59] | committer: Zane van Iperen

format/imfdec: improve error handling when selecting tracks for playback

Reviewed-by: Zane van Iperen <zane at zanevaniperen.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=0e402ebf487075727187c78f85908a492eed3e59
---

 libavformat/imfdec.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/libavformat/imfdec.c b/libavformat/imfdec.c
index fde91a6419..4e60dcc4ba 100644
--- a/libavformat/imfdec.c
+++ b/libavformat/imfdec.c
@@ -686,8 +686,11 @@ static IMFVirtualTrackPlaybackCtx *get_next_track_with_minimum_timestamp(AVForma
 {
     IMFContext *c = s->priv_data;
     IMFVirtualTrackPlaybackCtx *track;
-
     AVRational minimum_timestamp = av_make_q(INT32_MAX, 1);
+
+    if (!c->track_count)
+        return NULL;
+
     for (uint32_t i = c->track_count; i > 0; i--) {
         av_log(s, AV_LOG_TRACE, "Compare track %d timestamp " AVRATIONAL_FORMAT
                " to minimum " AVRATIONAL_FORMAT
@@ -702,8 +705,6 @@ static IMFVirtualTrackPlaybackCtx *get_next_track_with_minimum_timestamp(AVForma
         }
     }
 
-    av_log(s, AV_LOG_DEBUG, "Found next track to read: %d (timestamp: %lf / %lf)\n",
-           track->index, av_q2d(track->current_timestamp), av_q2d(minimum_timestamp));
     return track;
 }
 
@@ -766,6 +767,14 @@ static int imf_read_packet(AVFormatContext *s, AVPacket *pkt)
 
     track = get_next_track_with_minimum_timestamp(s);
 
+    if (!track) {
+        av_log(s, AV_LOG_ERROR, "No track found for playback\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    av_log(s, AV_LOG_DEBUG, "Found track %d to read at timestamp %lf\n",
+           track->index, av_q2d(track->current_timestamp));
+
     ret = get_resource_context_for_timestamp(s, track, &resource);
     if (ret)
         return ret;