X-Git-Url: http://git.tuebingen.mpg.de/?a=blobdiff_plain;f=mp4.c;h=9f11a66e52aca8b9e561542be7ba6d65b36d9d0b;hb=8cad8d7112afc13a906f5c20026262bccecd95b5;hp=1b387534d6adcbca4521472d473ebad49c7973cb;hpb=b3ac1dc38bb8366ece6cbaf2adf95e964e0295c7;p=paraslash.git

diff --git a/mp4.c b/mp4.c
index 1b387534..9f11a66e 100644
--- a/mp4.c
+++ b/mp4.c
@@ -8,6 +8,7 @@
 #include <regex.h>
 
 #include "para.h"
+#include "error.h"
 #include "portable_io.h"
 #include "string.h"
 #include "mp4.h"
@@ -988,9 +989,6 @@ static int32_t chunk_of_sample(const struct mp4 *f, int32_t track,
 
 	*chunk_sample = 0;
 	*chunk = 1;
-	if (f->track[track] == NULL) {
-		return -1;
-	}
 
 	total_entries = f->track[track]->stsc_entry_count;
 
@@ -1042,26 +1040,6 @@ static int32_t chunk_to_offset(const struct mp4 *f, int32_t track,
 	return 0;
 }
 
-static int32_t sample_range_size(const struct mp4 *f, int32_t track,
-		int32_t chunk_sample, int32_t sample)
-{
-	int32_t i, total;
-	const struct mp4_track *p_track = f->track[track];
-
-	if (p_track->stsz_sample_size) {
-		return (sample - chunk_sample) * p_track->stsz_sample_size;
-	} else {
-		if (sample >= p_track->stsz_sample_count)
-			return 0;	//error
-
-		for (i = chunk_sample, total = 0; i < sample; i++) {
-			total += p_track->stsz_table[i];
-		}
-	}
-
-	return total;
-}
-
 /**
  * Return the number of milliseconds of the given track.
  *
@@ -1099,14 +1077,24 @@ bool mp4_is_audio_track(const struct mp4 *f, int32_t track)
 	return f->track[track]->is_audio;
 }
 
-void mp4_set_sample_position(struct mp4 *f, int32_t track, int32_t sample)
+int mp4_set_sample_position(struct mp4 *f, uint32_t track, int32_t sample)
 {
+	const struct mp4_track *t = f->track[track];
 	int32_t offset, chunk, chunk_sample;
+	uint32_t n, srs; /* sample range size */
 
+	if (sample >= t->stsz_sample_count || track >= f->total_tracks)
+		return -ERRNO_TO_PARA_ERROR(EINVAL);
 	chunk_of_sample(f, track, sample, &chunk_sample, &chunk);
-	offset = chunk_to_offset(f, track, chunk)
-		+ sample_range_size(f, track, chunk_sample, sample);
+	if (t->stsz_sample_size > 0)
+		srs = (sample - chunk_sample) * t->stsz_sample_size;
+	else {
+		for (srs = 0, n = chunk_sample; n < sample; n++)
+			srs += t->stsz_table[n];
+	}
+	offset = chunk_to_offset(f, track, chunk) + srs;
 	set_position(f, offset);
+	return 1;
 }
 
 int32_t mp4_get_sample_size(const struct mp4 *f, int track, int sample)