From 1fadf53e0073176966e52d9a8ffd78ffe85e2d79 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Tomas=20H=C3=A4rdin?= Date: Fri, 2 Mar 2012 11:16:10 +0100 Subject: [PATCH] mxfdec: truncate packets that extend past the next edit unit This fixes rare cases where OPAtom may be treated as OP1a, causing all essence to be read into RAM. Signed-off-by: Michael Niedermayer Signed-off-by: Luca Barbato --- libavformat/mxfdec.c | 65 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 50 insertions(+), 15 deletions(-) diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c index f24e25f5bc..a0bbd7a335 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 +1941,30 @@ 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 +1979,20 @@ 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