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authorMika Raento <mikie@iki.fi>2014-10-08 09:39:26 +0300
committerMichael Niedermayer <michaelni@gmx.at>2014-10-09 12:15:48 +0200
commitd3834f290138cb8c48fd404081ac5b9a2ca14564 (patch)
tree5032f9ef85959c71b8447c674574ae894c8c4683 /tools
parent5d36e8527f08eeda5874dd27af133752015a01bf (diff)
downloadffmpeg-d3834f290138cb8c48fd404081ac5b9a2ca14564.tar.gz
ismindex: handle discontinuous streams better
Reads the fragment duration from the trun sample data, rather than assuming that there are no gaps. Creates much better playlists for our inputs. Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'tools')
-rw-r--r--tools/ismindex.c95
1 files changed, 85 insertions, 10 deletions
diff --git a/tools/ismindex.c b/tools/ismindex.c
index 734419b1c9..b9bcedebde 100644
--- a/tools/ismindex.c
+++ b/tools/ismindex.c
@@ -50,6 +50,7 @@
#include "cmdutils.h"
#include "libavformat/avformat.h"
+#include "libavformat/isom.h"
#include "libavformat/os_support.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/mathematics.h"
@@ -226,6 +227,78 @@ fail:
return ret;
}
+static int64_t read_trun_duration(AVIOContext *in, int64_t end)
+{
+ int64_t ret = 0;
+ int64_t pos;
+ int flags, i;
+ int entries;
+ avio_r8(in); /* version */
+ flags = avio_rb24(in);
+ if (! (flags & MOV_TRUN_SAMPLE_DURATION)) {
+ fprintf(stderr, "no sample duration in trun flags");
+ return -1;
+ }
+ entries = avio_rb32(in);
+
+ if (flags & MOV_TRUN_DATA_OFFSET) avio_rb32(in);
+ if (flags & MOV_TRUN_FIRST_SAMPLE_FLAGS) avio_rb32(in);
+
+ pos = avio_tell(in);
+ for (i = 0; i < entries && pos < end; i++) {
+ int sample_duration = 0;
+ if (flags & MOV_TRUN_SAMPLE_DURATION) sample_duration = avio_rb32(in);
+ if (flags & MOV_TRUN_SAMPLE_SIZE) avio_rb32(in);
+ if (flags & MOV_TRUN_SAMPLE_FLAGS) avio_rb32(in);
+ if (flags & MOV_TRUN_SAMPLE_CTS) avio_rb32(in);
+ if (sample_duration < 0) {
+ fprintf(stderr, "negative sample duration %d\n", sample_duration);
+ return -1;
+ }
+ ret += sample_duration;
+ pos = avio_tell(in);
+ }
+
+ return ret;
+}
+
+static int64_t read_moof_duration(AVIOContext *in, int64_t offset)
+{
+ int64_t ret = -1;
+ int32_t moof_size, size, tag;
+ int64_t pos = 0;
+
+ avio_seek(in, offset, SEEK_SET);
+ moof_size = avio_rb32(in);
+ tag = avio_rb32(in);
+ if (expect_tag(tag, MKBETAG('m', 'o', 'o', 'f')) != 0) goto fail;
+ while (pos < offset + moof_size) {
+ pos = avio_tell(in);
+ size = avio_rb32(in);
+ tag = avio_rb32(in);
+ if (tag == MKBETAG('t', 'r', 'a', 'f')) {
+ int64_t traf_pos = pos;
+ int64_t traf_size = size;
+ while (pos < traf_pos + traf_size) {
+ pos = avio_tell(in);
+ size = avio_rb32(in);
+ tag = avio_rb32(in);
+ if (tag == MKBETAG('t', 'r', 'u', 'n')) {
+ return read_trun_duration(in, pos + size);
+ }
+ avio_seek(in, pos + size, SEEK_SET);
+ }
+ fprintf(stderr, "couldn't find trun");
+ goto fail;
+ }
+ avio_seek(in, pos + size, SEEK_SET);
+ }
+ fprintf(stderr, "couldn't find traf");
+
+fail:
+ return ret;
+}
+
static int read_tfra(struct Tracks *tracks, int start_index, AVIOContext *f)
{
int ret = AVERROR_EOF, track_id;
@@ -255,12 +328,7 @@ static int read_tfra(struct Tracks *tracks, int start_index, AVIOContext *f)
goto fail;
}
// The duration here is always the difference between consecutive
- // start times and doesn't even try to read the actual duration of the
- // media fragments. This is what other smooth streaming tools tend to
- // do too, but cannot express missing fragments, and the start times
- // may not match the stream metadata we get from libavformat. Correct
- // calculation would require parsing the tfxd atom (if present, it's
- // not mandatory) or parsing the full moof atoms separately.
+ // start times.
for (i = 0; i < track->chunks; i++) {
if (version == 1) {
track->offsets[i].time = avio_rb64(f);
@@ -283,6 +351,17 @@ static int read_tfra(struct Tracks *tracks, int start_index, AVIOContext *f)
track->offsets[track->chunks - 1].duration = track->offsets[0].time +
track->duration -
track->offsets[track->chunks - 1].time;
+ }
+ // Now try and read the actual durations from the trun sample data.
+ for (i = 0; i < track->chunks; i++) {
+ int64_t duration = read_moof_duration(f, track->offsets[i].offset);
+ if (duration > 0 && abs(duration - track->offsets[i].duration) > 3) {
+ // 3 allows for integer duration to drift a few units,
+ // e.g., for 1/3 durations
+ track->offsets[i].duration = duration;
+ }
+ }
+ if (track->chunks > 0) {
if (track->offsets[track->chunks - 1].duration <= 0) {
fprintf(stderr, "Calculated last chunk duration for track %d "
"was non-positive (%"PRId64"), probably due to missing "
@@ -577,10 +656,6 @@ static void print_track_chunks(FILE *out, struct Tracks *tracks, int main,
fprintf(out, "\t\t<c n=\"%d\" d=\"%"PRId64"\" ",
i, track->offsets[i].duration);
if (pos != track->offsets[i].time) {
- // With the current logic for calculation of durations from
- // chunk start times, this branch can only be hit on the first
- // chunk - but that's still useful and this will keep working
- // if the duration calculation is improved.
fprintf(out, "t=\"%"PRId64"\" ", track->offsets[i].time);
pos = track->offsets[i].time;
}