mpegaudioparse: use metadata (xing, vbri) provided bytesize for conversions

Metadata provided seek tables are consistent with metadata's view of
total size, which typically matches real size, but need not do so
(e.g. a truncated file).  Fixes seeking and position reporting
in such truncated files (although duration based on metadata may then
still be incorrect).

1 files changed, 17 insertions, 3 deletions

diff --git a/gst/mpegaudioparse/gstmpegaudioparse.c b/gst/mpegaudioparse/gstmpegaudioparse.c
index 54949d15..f7c18a31 100644
--- a/gst/mpegaudioparse/gstmpegaudioparse.c
+++ b/gst/mpegaudioparse/gstmpegaudioparse.c
@@ -1620,6 +1620,9 @@ mp3parse_time_to_bytepos (GstMPEGAudioParse * mp3parse, GstClockTime ts,
         gst_util_guint64_to_gdouble (total_time), 0.0, 100.0);
     gint index = CLAMP (percent, 0, 99);
 
+    /* xing indicated size is preferred over e.g. truncated file size */
+    if (mp3parse->xing_bytes)
+      total_bytes = mp3parse->xing_bytes;
     fa = mp3parse->xing_seek_table[index];
     if (index < 99)
       fb = mp3parse->xing_seek_table[index + 1];
@@ -1639,6 +1642,9 @@ mp3parse_time_to_bytepos (GstMPEGAudioParse * mp3parse, GstClockTime ts,
     gint i, j;
     gdouble a, b, fa, fb;
 
+    /* header indicated size is preferred over e.g. truncated file size */
+    if (mp3parse->vbri_bytes)
+      total_bytes = mp3parse->vbri_bytes;
     i = gst_util_uint64_scale (ts, mp3parse->vbri_seek_points - 1, total_time);
     i = CLAMP (i, 0, mp3parse->vbri_seek_points - 1);
 
@@ -1695,9 +1701,14 @@ mp3parse_bytepos_to_time (GstMPEGAudioParse * mp3parse,
       mp3parse_total_bytes (mp3parse, &total_bytes) &&
       mp3parse_total_time (mp3parse, &total_time)) {
     gdouble fa, fb, fx;
-    gdouble pos = CLAMP ((bytepos * 256.0) / total_bytes, 0.0, 256.0);
-    gint index = CLAMP (pos, 0, 255);
-
+    gdouble pos;
+    gint index;
+
+    /* xing indicated size is preferred over e.g. truncated file size */
+    if (mp3parse->xing_bytes)
+      total_bytes = mp3parse->xing_bytes;
+    pos = CLAMP ((bytepos * 256.0) / total_bytes, 0.0, 256.0);
+    index = CLAMP (pos, 0, 255);
     fa = mp3parse->xing_seek_table_inverse[index];
     if (index < 255)
       fb = mp3parse->xing_seek_table_inverse[index + 1];
@@ -1718,6 +1729,9 @@ mp3parse_bytepos_to_time (GstMPEGAudioParse * mp3parse,
     guint64 sum = 0;
     gdouble a, b, fa, fb;
 
+    /* header indicated size is preferred over e.g. truncated file size */
+    if (mp3parse->vbri_bytes)
+      total_bytes = mp3parse->vbri_bytes;
     do {
       sum += mp3parse->vbri_seek_table[i];
       i++;