[FFmpeg-cvslog] mxfdec: Hybrid demuxing/seeking solution

Tomas Härdin git at videolan.org
Sun Dec 18 23:30:44 CET 2011


ffmpeg | branch: master | Tomas Härdin <tomas.hardin at codemill.se> | Fri Dec 16 10:53:41 2011 +0100| [2eba8da67572c7e9fa06191fd86312ae42116630] | committer: Tomas Härdin

mxfdec: Hybrid demuxing/seeking solution

This uses the old demuxing code for OP1a and separate demuxing code for OPAtom.
Timestamp output is added to the old demuxing code.
The seeking code is made to seek to the start of the desired EditUnit only,
from which the normal demuxing code takes over (if OP1a). This means we don't
use delta entries or slices, only StreamOffsets.
OPAtom seeking basically works like before.
This also makes D-10 seeking behave the same way as OP1a and OPAtom. In other
words, we allow seeking before the start or past the end for D-10 too.
This fixes ticket #746.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=2eba8da67572c7e9fa06191fd86312ae42116630
---

 libavformat/mxfdec.c        |  161 +++++++++++++++++++++++++++---------------
 tests/ref/seek/lavf_mxf     |   44 ++++++------
 tests/ref/seek/lavf_mxf_d10 |   36 +++++-----
 3 files changed, 143 insertions(+), 98 deletions(-)

diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index 98a7145..bf70d7c 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -1014,6 +1014,29 @@ static int64_t mxf_essence_container_length(MXFContext *mxf, int body_sid)
     return ret;
 }
 
+/**
+ * Returns the end position of the essence container with given BodySID, or zero if unknown
+ */
+static int64_t mxf_essence_container_end(MXFContext *mxf, int body_sid)
+{
+    int x;
+    int64_t ret = 0;
+
+    for (x = 0; x < mxf->partitions_count; x++) {
+        MXFPartition *p = &mxf->partitions[x];
+
+        if (p->body_sid != body_sid)
+            continue;
+
+        if (!p->essence_length)
+            return 0;
+
+        ret = p->essence_offset + p->essence_length;
+    }
+
+    return ret;
+}
+
 /* EditUnit -> absolute offset */
 static int mxf_edit_unit_absolute_offset(MXFContext *mxf, MXFIndexTable *index_table, int64_t edit_unit, int64_t *edit_unit_out, int64_t *offset_out, int nag)
 {
@@ -1888,6 +1911,32 @@ static int mxf_read_header(AVFormatContext *s, AVFormatParameters *ap)
     return 0;
 }
 
+/**
+ * Computes DTS and PTS for the given video packet based on its offset.
+ */
+static void mxf_packet_timestamps(MXFContext *mxf, AVPacket *pkt)
+{
+    int64_t next_ofs;
+    MXFIndexTable *t = &mxf->index_tables[0];
+
+    /* find mxf->current_edit_unit so that the next edit unit starts ahead of pkt->pos */
+    for (;;) {
+        if (mxf_edit_unit_absolute_offset(mxf, t, mxf->current_edit_unit + 1, NULL, &next_ofs, 0) < 0)
+            break;
+
+        if (next_ofs > pkt->pos)
+            break;
+
+        mxf->current_edit_unit++;
+    }
+
+    if (mxf->current_edit_unit >= t->nb_ptses)
+        return;
+
+    pkt->dts = mxf->current_edit_unit + t->first_dts;
+    pkt->pts = t->ptses[mxf->current_edit_unit];
+}
+
 static int mxf_read_packet_old(AVFormatContext *s, AVPacket *pkt)
 {
     KLVPacket klv;
@@ -1927,6 +1976,10 @@ 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 */
+
             return 0;
         } else
         skip:
@@ -1938,63 +1991,51 @@ static int mxf_read_packet_old(AVFormatContext *s, AVPacket *pkt)
 static int mxf_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     MXFContext *mxf = s->priv_data;
-    AVIndexEntry *e;
-    int ret;
-    int64_t ret64;
-    KLVPacket klv;
+    int ret, size;
+    int64_t ret64, pos, next_pos;
     AVStream *st;
+    MXFIndexTable *t;
 
-    /* TODO: better logic for this?
-     * only files that lack all index segments prior to the essence need this */
-    if (!s->pb->seekable && mxf->op != OPAtom || mxf->d10 || mxf->broken_index)
+    if (mxf->op != OPAtom)
         return mxf_read_packet_old(s, pkt);
 
-    if (mxf->current_stream >= s->nb_streams) {
-        mxf->current_edit_unit++;
-        mxf->current_stream = 0;
-    }
+    /* OPAtom - clip wrapped demuxing */
+    st = s->streams[0];
+    t = &mxf->index_tables[0];
 
-    st = s->streams[mxf->current_stream];
-
-    if (mxf->current_edit_unit >= st->nb_index_entries)
+    if (mxf->current_edit_unit >= st->duration)
         return AVERROR_EOF;
 
-    e = &st->index_entries[mxf->current_edit_unit];
+    if ((ret = mxf_edit_unit_absolute_offset(mxf, t, mxf->current_edit_unit, NULL, &pos, 1)) < 0)
+        return ret;
 
-    if ((ret64 = avio_seek(s->pb, e->pos, SEEK_SET)) < 0)
-        return ret64;
+    /* compute size by finding the next edit unit or the end of the essence container
+     * not pretty, but it works */
+    if ((ret = mxf_edit_unit_absolute_offset(mxf, t, mxf->current_edit_unit + 1, NULL, &next_pos, 0)) < 0 &&
+        (next_pos = mxf_essence_container_end(mxf, t->body_sid)) <= 0) {
+        av_log(s, AV_LOG_ERROR, "unable to compute the size of the last packet\n");
+        return AVERROR_INVALIDDATA;
+    }
 
-    if (mxf->op == OPAtom) {
-        /* OPAtom - no KL, just essence */
-        if ((ret = av_get_packet(s->pb, pkt, e->size)) != e->size)
-            return ret < 0 ? ret : AVERROR_EOF;
-    } else {
-        /* read KL, read L bytes of essence */
-        if ((ret = klv_read_packet(&klv, s->pb)) < 0)
-            return ret;
+    if ((size = next_pos - pos) <= 0) {
+        av_log(s, AV_LOG_ERROR, "bad size: %i\n", size);
+        return AVERROR_INVALIDDATA;
+    }
 
-        /* untested, but looks OK */
-        if (IS_KLV_KEY(klv.key, mxf_encrypted_triplet_key)) {
-            int res = mxf_decrypt_triplet(s, pkt, &klv);
-            if (res < 0) {
-                av_log(s, AV_LOG_ERROR, "invalid encoded triplet\n");
-                return -1;
-            }
-            return 0;
-        }
+    if ((ret64 = avio_seek(s->pb, pos, SEEK_SET)) < 0)
+        return ret64;
 
-        if ((ret = av_get_packet(s->pb, pkt, klv.length)) != klv.length)
+        if ((ret = av_get_packet(s->pb, pkt, size)) != size)
             return ret < 0 ? ret : AVERROR_EOF;
 
-        pkt->pos = e->pos;
-    }
-
-    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && mxf->ptses && mxf->current_edit_unit < mxf->nb_ptses) {
-        pkt->dts = mxf->current_edit_unit + mxf->first_dts;
-        pkt->pts = mxf->ptses[mxf->current_edit_unit];
+    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && t->ptses &&
+        mxf->current_edit_unit >= 0 && mxf->current_edit_unit < t->nb_ptses) {
+        pkt->dts = mxf->current_edit_unit + t->first_dts;
+        pkt->pts = t->ptses[mxf->current_edit_unit];
     }
 
-    pkt->stream_index = mxf->current_stream++;
+    pkt->stream_index = 0;
+    mxf->current_edit_unit++;
 
     return 0;
 }
@@ -2078,9 +2119,10 @@ static int mxf_read_seek(AVFormatContext *s, int stream_index, int64_t sample_ti
     int64_t seconds;
     MXFContext* mxf = s->priv_data;
     int64_t seekpos;
-    int index;
+    int ret;
+    MXFIndexTable *t;
 
-    if (mxf->d10) {
+    if (mxf->index_tables <= 0) {
     if (!s->bit_rate)
         return -1;
     if (sample_time < 0)
@@ -2090,24 +2132,27 @@ static int mxf_read_seek(AVFormatContext *s, int stream_index, int64_t sample_ti
         return -1;
     ff_update_cur_dts(s, st, sample_time);
     } else {
-        if (st->nb_index_entries <= 0)
-            return -1;
+        t = &mxf->index_tables[0];
 
-        index = av_index_search_timestamp(st, sample_time, flags);
+        /* clamp above zero, else ff_index_search_timestamp() returns negative
+         * this also means we allow seeking before the start */
+        sample_time = FFMAX(sample_time, 0);
 
-        av_dlog(s, "stream %d, timestamp %"PRId64", sample %d\n", st->index, sample_time, index);
-
-        if (index < 0) {
-            if (sample_time < st->index_entries[0].timestamp)
-                index = 0;
-            else
-                return -1;
+        if (t->fake_index) {
+            /* behave as if we have a proper index */
+            if ((sample_time = ff_index_search_timestamp(t->fake_index, t->nb_ptses, sample_time, flags)) < 0)
+                return sample_time;
+        } else {
+            /* no IndexEntryArray (one or more CBR segments)
+             * make sure we don't seek past the end */
+            sample_time = FFMIN(sample_time, st->duration - 1);
         }
 
-        seekpos = st->index_entries[index].pos;
-        av_update_cur_dts(s, st, st->index_entries[index].timestamp);
-        mxf->current_edit_unit = st->index_entries[index].timestamp;
-        mxf->current_stream = 0;
+        if ((ret = mxf_edit_unit_absolute_offset(mxf, t, sample_time, &sample_time, &seekpos, 1)) << 0)
+            return ret;
+
+        av_update_cur_dts(s, st, sample_time);
+        mxf->current_edit_unit = sample_time;
         avio_seek(s->pb, seekpos, SEEK_SET);
     }
     return 0;
diff --git a/tests/ref/seek/lavf_mxf b/tests/ref/seek/lavf_mxf
index 00dea3d..cc634a8 100644
--- a/tests/ref/seek/lavf_mxf
+++ b/tests/ref/seek/lavf_mxf
@@ -1,48 +1,48 @@
-ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:   6144 size: 24801
+ret: 0         st: 0 flags:1 dts:-0.040000 pts: 0.000000 pos:   6144 size: 24801
 ret: 0         st:-1 flags:0  ts:-1.000000
-ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:   6144 size: 24801
+ret: 0         st: 0 flags:1 dts:-0.040000 pts: 0.000000 pos:   6144 size: 24801
 ret: 0         st:-1 flags:1  ts: 1.894167
-ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 460800 size: 24712
+ret: 0         st: 0 flags:1 dts: 0.840000 pts: 0.960000 pos: 460800 size: 24712
 ret: 0         st: 0 flags:0  ts: 0.800000
-ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 460800 size: 24712
+ret: 0         st: 0 flags:1 dts: 0.840000 pts: 0.960000 pos: 460800 size: 24712
 ret: 0         st: 0 flags:1  ts:-0.320000
-ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:   6144 size: 24801
+ret: 0         st: 0 flags:1 dts:-0.040000 pts: 0.000000 pos:   6144 size: 24801
 ret:-1         st: 1 flags:0  ts: 2.560000
 ret: 0         st: 1 flags:1  ts: 1.480000
-ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 460800 size: 24712
+ret: 0         st: 0 flags:1 dts: 0.840000 pts: 0.960000 pos: 460800 size: 24712
 ret: 0         st:-1 flags:0  ts: 0.365002
-ret: 0         st: 0 flags:1 dts: 0.400000 pts: NOPTS    pos: 211968 size: 24787
+ret: 0         st: 0 flags:1 dts: 0.360000 pts: 0.480000 pos: 211968 size: 24787
 ret: 0         st:-1 flags:1  ts:-0.740831
-ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:   6144 size: 24801
+ret: 0         st: 0 flags:1 dts:-0.040000 pts: 0.000000 pos:   6144 size: 24801
 ret:-1         st: 0 flags:0  ts: 2.160000
 ret: 0         st: 0 flags:1  ts: 1.040000
-ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 460800 size: 24712
+ret: 0         st: 0 flags:1 dts: 0.840000 pts: 0.960000 pos: 460800 size: 24712
 ret: 0         st: 1 flags:0  ts:-0.040000
-ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:   6144 size: 24801
+ret: 0         st: 0 flags:1 dts:-0.040000 pts: 0.000000 pos:   6144 size: 24801
 ret: 0         st: 1 flags:1  ts: 2.840000
-ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 460800 size: 24712
+ret: 0         st: 0 flags:1 dts: 0.840000 pts: 0.960000 pos: 460800 size: 24712
 ret:-1         st:-1 flags:0  ts: 1.730004
 ret: 0         st:-1 flags:1  ts: 0.624171
-ret: 0         st: 0 flags:1 dts: 0.400000 pts: NOPTS    pos: 211968 size: 24787
+ret: 0         st: 0 flags:1 dts: 0.360000 pts: 0.480000 pos: 211968 size: 24787
 ret: 0         st: 0 flags:0  ts:-0.480000
-ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:   6144 size: 24801
+ret: 0         st: 0 flags:1 dts:-0.040000 pts: 0.000000 pos:   6144 size: 24801
 ret: 0         st: 0 flags:1  ts: 2.400000
-ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 460800 size: 24712
+ret: 0         st: 0 flags:1 dts: 0.840000 pts: 0.960000 pos: 460800 size: 24712
 ret:-1         st: 1 flags:0  ts: 1.320000
 ret: 0         st: 1 flags:1  ts: 0.200000
-ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:   6144 size: 24801
+ret: 0         st: 0 flags:1 dts:-0.040000 pts: 0.000000 pos:   6144 size: 24801
 ret: 0         st:-1 flags:0  ts:-0.904994
-ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:   6144 size: 24801
+ret: 0         st: 0 flags:1 dts:-0.040000 pts: 0.000000 pos:   6144 size: 24801
 ret: 0         st:-1 flags:1  ts: 1.989173
-ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 460800 size: 24712
+ret: 0         st: 0 flags:1 dts: 0.840000 pts: 0.960000 pos: 460800 size: 24712
 ret: 0         st: 0 flags:0  ts: 0.880000
-ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 460800 size: 24712
+ret: 0         st: 0 flags:1 dts: 0.840000 pts: 0.960000 pos: 460800 size: 24712
 ret: 0         st: 0 flags:1  ts:-0.240000
-ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:   6144 size: 24801
+ret: 0         st: 0 flags:1 dts:-0.040000 pts: 0.000000 pos:   6144 size: 24801
 ret:-1         st: 1 flags:0  ts: 2.680000
 ret: 0         st: 1 flags:1  ts: 1.560000
-ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 460800 size: 24712
+ret: 0         st: 0 flags:1 dts: 0.840000 pts: 0.960000 pos: 460800 size: 24712
 ret: 0         st:-1 flags:0  ts: 0.460008
-ret: 0         st: 0 flags:1 dts: 0.880000 pts: NOPTS    pos: 460800 size: 24712
+ret: 0         st: 0 flags:1 dts: 0.840000 pts: 0.960000 pos: 460800 size: 24712
 ret: 0         st:-1 flags:1  ts:-0.645825
-ret: 0         st: 0 flags:1 dts: 0.000000 pts: NOPTS    pos:   6144 size: 24801
+ret: 0         st: 0 flags:1 dts:-0.040000 pts: 0.000000 pos:   6144 size: 24801
diff --git a/tests/ref/seek/lavf_mxf_d10 b/tests/ref/seek/lavf_mxf_d10
index c05870f..4cfe595 100644
--- a/tests/ref/seek/lavf_mxf_d10
+++ b/tests/ref/seek/lavf_mxf_d10
@@ -2,52 +2,52 @@ ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:   6144 size:150000
 ret: 0         st:-1 flags:0  ts:-1.000000
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:   6144 size:150000
 ret: 0         st:-1 flags:1  ts: 1.894167
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st: 0 flags:0  ts: 0.800000
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.800000 pts: 0.800000 pos:4265984 size:150000
 ret: 0         st: 0 flags:1  ts:-0.320000
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:   6144 size:150000
 ret: 0         st: 1 flags:0  ts: 2.560000
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st: 1 flags:1  ts: 1.480000
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st:-1 flags:0  ts: 0.365002
-ret: 0         st: 0 flags:1 dts: 0.360000 pts: 0.360000 pos:   6144 size:150000
+ret: 0         st: 0 flags:1 dts: 0.360000 pts: 0.360000 pos:1923072 size:150000
 ret: 0         st:-1 flags:1  ts:-0.740831
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:   6144 size:150000
 ret: 0         st: 0 flags:0  ts: 2.160000
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st: 0 flags:1  ts: 1.040000
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st: 1 flags:0  ts:-0.040000
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:   6144 size:150000
 ret: 0         st: 1 flags:1  ts: 2.840000
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st:-1 flags:0  ts: 1.730004
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st:-1 flags:1  ts: 0.624171
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.640000 pts: 0.640000 pos:3414016 size:150000
 ret: 0         st: 0 flags:0  ts:-0.480000
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:   6144 size:150000
 ret: 0         st: 0 flags:1  ts: 2.400000
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st: 1 flags:0  ts: 1.320000
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st: 1 flags:1  ts: 0.200000
-ret: 0         st: 0 flags:1 dts: 0.200000 pts: 0.200000 pos:   6144 size:150000
+ret: 0         st: 0 flags:1 dts: 0.200000 pts: 0.200000 pos:1071104 size:150000
 ret: 0         st:-1 flags:0  ts:-0.904994
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:   6144 size:150000
 ret: 0         st:-1 flags:1  ts: 1.989173
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st: 0 flags:0  ts: 0.880000
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.880000 pts: 0.880000 pos:4691968 size:150000
 ret: 0         st: 0 flags:1  ts:-0.240000
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:   6144 size:150000
 ret: 0         st: 1 flags:0  ts: 2.680000
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st: 1 flags:1  ts: 1.560000
-ret:-1
+ret: 0         st: 0 flags:1 dts: 0.960000 pts: 0.960000 pos:5117952 size:150000
 ret: 0         st:-1 flags:0  ts: 0.460008
-ret: 0         st: 0 flags:1 dts: 0.480000 pts: 0.480000 pos:   6144 size:150000
+ret: 0         st: 0 flags:1 dts: 0.480000 pts: 0.480000 pos:2562048 size:150000
 ret: 0         st:-1 flags:1  ts:-0.645825
 ret: 0         st: 0 flags:1 dts: 0.000000 pts: 0.000000 pos:   6144 size:150000



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