From: Tomas Härdin <tomas.har...@codemill.se>
This fixes rare cases where OPAtom may be treated as OP1a, causing all essence
to be read into RAM.
Signed-off-by: Michael Niedermayer <michae...@gmx.at>
Signed-off-by: Luca Barbato <lu_z...@gentoo.org>
---
libavformat/mxfdec.c | 64 ++++++++++++++++++++++++++++++++++++++-----------
1 files changed, 49 insertions(+), 15 deletions(-)
diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index f24e25f..63221bd 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -1877,48 +1877,53 @@ static int mxf_read_header(AVFormatContext *s)
}
/**
- * Computes DTS and PTS for the given video packet based on its offset.
+ * Sets mxf->current_edit_unit based on what offset we're currently at.
+ * @return next_ofs if OK, <0 on error
*/
-static void mxf_packet_timestamps(MXFContext *mxf, AVPacket *pkt)
+static int64_t mxf_set_current_edit_unit(MXFContext *mxf, int64_t
current_offset)
{
- int64_t last_ofs = -1, next_ofs;
+ int64_t last_ofs = -1, next_ofs = -1;
MXFIndexTable *t = &mxf->index_tables[0];
/* this is called from the OP1a demuxing logic, which means there
* may be no index tables */
if (mxf->nb_index_tables <= 0)
- return;
+ return -1;
- /* find mxf->current_edit_unit so that the next edit unit starts ahead of
pkt->pos */
+ /* find mxf->current_edit_unit so that the next edit unit starts ahead
+ * of current_offset */
while (mxf->current_edit_unit >= 0) {
- if (mxf_edit_unit_absolute_offset(mxf, t, mxf->current_edit_unit + 1,
NULL, &next_ofs, 0) < 0)
- break;
+ if (mxf_edit_unit_absolute_offset(mxf, t, mxf->current_edit_unit + 1,
+ NULL, &next_ofs, 0) < 0)
+ return -1;
if (next_ofs <= last_ofs) {
/* large next_ofs didn't change or current_edit_unit wrapped
* around this fixes the infinite loop on zzuf3.mxf */
av_log(mxf->fc, AV_LOG_ERROR,
"next_ofs didn't change. not deriving packet timestamps\n");
- return;
+ return -1;
}
- if (next_ofs > pkt->pos)
+ if (next_ofs > current_offset)
break;
last_ofs = next_ofs;
mxf->current_edit_unit++;
}
- if (mxf->current_edit_unit < 0 || mxf->current_edit_unit >= t->nb_ptses)
- return;
+ /* not checking mxf->current_edit_unit >= t->nb_ptses here since CBR files
+ * may lack IndexEntryArrays */
+ if (mxf->current_edit_unit < 0)
+ return -1;
- pkt->dts = mxf->current_edit_unit + t->first_dts;
- pkt->pts = t->ptses[mxf->current_edit_unit];
+ return next_ofs;
}
static int mxf_read_packet_old(AVFormatContext *s, AVPacket *pkt)
{
KLVPacket klv;
+ MXFContext *mxf = s->priv_data;
while (!s->pb->eof_reached) {
if (klv_read_packet(&klv, s->pb) < 0)
@@ -1936,12 +1941,29 @@ static int mxf_read_packet_old(AVFormatContext *s,
AVPacket *pkt)
if (IS_KLV_KEY(klv.key, mxf_essence_element_key) ||
IS_KLV_KEY(klv.key, mxf_avid_essence_element_key)) {
int index = mxf_get_stream_index(s, &klv);
+ int64_t next_ofs, next_klv;
+
if (index < 0) {
av_log(s, AV_LOG_ERROR, "error getting stream index %d\n",
AV_RB32(klv.key+12));
goto skip;
}
if (s->streams[index]->discard == AVDISCARD_ALL)
goto skip;
+
+ next_klv = avio_tell(s->pb) + klv.length;
+ next_ofs = mxf_set_current_edit_unit(mxf, klv.offset);
+
+ if (next_ofs >= 0 && next_klv > next_ofs) {
+ /* if this check is hit then it's possible OPAtom was treated
+ * as OP1a truncate the packet since it's probably very large
+ * (>2 GiB is common) */
+ av_log_ask_for_sample(s,
+ "KLV for edit unit %i extends into next edit unit "
+ "- OPAtom misinterpreted as OP1a?\n",
+ mxf->current_edit_unit);
+ klv.length = next_ofs - avio_tell(s->pb);
+ }
+
/* check for 8 channels AES3 element */
if (klv.key[12] == 0x06 && klv.key[13] == 0x01 && klv.key[14] ==
0x10) {
if (mxf_get_d10_aes3_packet(s->pb, s->streams[index], pkt,
klv.length) < 0) {
@@ -1956,8 +1978,20 @@ static int mxf_read_packet_old(AVFormatContext *s,
AVPacket *pkt)
pkt->stream_index = index;
pkt->pos = klv.offset;
- if (s->streams[index]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
- mxf_packet_timestamps(s->priv_data, pkt); /* offset ->
EditUnit -> DTS/PTS */
+ if (s->streams[index]->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
next_ofs >= 0) {
+ /* mxf->current_edit_unit good - see if we have an
+ * index table to derive timestamps from */
+ MXFIndexTable *t = &mxf->index_tables[0];
+
+ if (mxf->nb_index_tables >= 1 &&
+ mxf->current_edit_unit < t->nb_ptses) {
+ pkt->dts = mxf->current_edit_unit + t->first_dts;
+ pkt->pts = t->ptses[mxf->current_edit_unit];
+ }
+ }
+
+ /* seek for truncated packets */
+ avio_seek(s->pb, next_klv, SEEK_SET);
return 0;
} else
--
1.7.8.rc1
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