ffmpeg | branch: release/4.2 | Andreas Rheinhardt <andreas.rheinha...@gmail.com> | Mon Dec 30 15:59:02 2019 +0100| [477275795865f074e60635d813a7b765284ca948] | committer: Andreas Rheinhardt
avformat/matroskaenc: Write level 1 elements in one go Up until now, writing level 1 elements proceeded as follows: First, the element id was written to the ordinary output AVIOContext and a dynamic buffer was opened for the content of the level 1 element in start_ebml_master_crc32(). Then this buffer was actually used and after it was closed (in end_ebml_master_crc32()), the size field corresponding to the buffer's size was written, after which the actual data was written. This commit changes this: Nothing is written to the main AVIOContext any more in start_ebml_master_crc32(). end_ebml_master_crc32() now writes both the id, the length field as well as the data. This is benefical for streaming, because a client that receives just a Cluster ID and nothing more might infer that this is EOF; in certain usecases there is also the danger of a client receiving the Cluster without the actual Cluster ID at the beginning. Addresses #8578. (cherry picked from commit d9c21ec) Signed-off-by: Andreas Rheinhardt <andreas.rheinha...@gmail.com> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=477275795865f074e60635d813a7b765284ca948 --- libavformat/matroskaenc.c | 63 +++++++++++++++++++++++++---------------------- 1 file changed, 34 insertions(+), 29 deletions(-) diff --git a/libavformat/matroskaenc.c b/libavformat/matroskaenc.c index cef504fa05..2e63b90b28 100644 --- a/libavformat/matroskaenc.c +++ b/libavformat/matroskaenc.c @@ -331,26 +331,26 @@ static void end_ebml_master(AVIOContext *pb, ebml_master master) avio_seek(pb, pos, SEEK_SET); } -static int start_ebml_master_crc32(AVIOContext *pb, AVIOContext **dyn_cp, MatroskaMuxContext *mkv, - uint32_t elementid) +static int start_ebml_master_crc32(AVIOContext **dyn_cp, MatroskaMuxContext *mkv) { int ret; if ((ret = avio_open_dyn_buf(dyn_cp)) < 0) return ret; - put_ebml_id(pb, elementid); if (mkv->write_crc) put_ebml_void(*dyn_cp, 6); /* Reserve space for CRC32 so position/size calculations using avio_tell() take it into account */ return 0; } -static void end_ebml_master_crc32(AVIOContext *pb, AVIOContext **dyn_cp, MatroskaMuxContext *mkv) +static void end_ebml_master_crc32(AVIOContext *pb, AVIOContext **dyn_cp, + MatroskaMuxContext *mkv, uint32_t id) { uint8_t *buf, crc[4]; int size, skip = 0; + put_ebml_id(pb, id); size = avio_close_dyn_buf(*dyn_cp, &buf); put_ebml_num(pb, size, 0); if (mkv->write_crc) { @@ -368,13 +368,14 @@ static void end_ebml_master_crc32(AVIOContext *pb, AVIOContext **dyn_cp, Matrosk * Complete ebml master without destroying the buffer, allowing for later updates */ static void end_ebml_master_crc32_preliminary(AVIOContext *pb, AVIOContext **dyn_cp, MatroskaMuxContext *mkv, - int64_t *pos) + uint32_t id, int64_t *pos) { uint8_t *buf; int size = avio_get_dyn_buf(*dyn_cp, &buf); *pos = avio_tell(pb); + put_ebml_id(pb, id); put_ebml_num(pb, size, 0); avio_write(pb, buf, size); } @@ -500,7 +501,7 @@ static int64_t mkv_write_seekhead(AVIOContext *pb, MatroskaMuxContext *mkv) } } - if (start_ebml_master_crc32(pb, &dyn_cp, mkv, MATROSKA_ID_SEEKHEAD) < 0) { + if (start_ebml_master_crc32(&dyn_cp, mkv) < 0) { currentpos = -1; goto fail; } @@ -517,7 +518,7 @@ static int64_t mkv_write_seekhead(AVIOContext *pb, MatroskaMuxContext *mkv) put_ebml_uint(dyn_cp, MATROSKA_ID_SEEKPOSITION, entry->segmentpos); end_ebml_master(dyn_cp, seekentry); } - end_ebml_master_crc32(pb, &dyn_cp, mkv); + end_ebml_master_crc32(pb, &dyn_cp, mkv, MATROSKA_ID_SEEKHEAD); if (seekhead->reserved_size > 0) { uint64_t remaining = seekhead->filepos + seekhead->reserved_size - avio_tell(pb); @@ -574,7 +575,7 @@ static int64_t mkv_write_cues(AVFormatContext *s, mkv_cues *cues, mkv_track *tra int i, j, ret; currentpos = avio_tell(pb); - ret = start_ebml_master_crc32(pb, &dyn_cp, mkv, MATROSKA_ID_CUES); + ret = start_ebml_master_crc32(&dyn_cp, mkv); if (ret < 0) return ret; @@ -620,7 +621,7 @@ static int64_t mkv_write_cues(AVFormatContext *s, mkv_cues *cues, mkv_track *tra i += j - 1; end_ebml_master(dyn_cp, cuepoint); } - end_ebml_master_crc32(pb, &dyn_cp, mkv); + end_ebml_master_crc32(pb, &dyn_cp, mkv, MATROSKA_ID_CUES); return currentpos; } @@ -1450,7 +1451,7 @@ static int mkv_write_tracks(AVFormatContext *s) if (ret < 0) return ret; - ret = start_ebml_master_crc32(pb, &mkv->tracks_bc, mkv, MATROSKA_ID_TRACKS); + ret = start_ebml_master_crc32(&mkv->tracks_bc, mkv); if (ret < 0) return ret; @@ -1465,9 +1466,10 @@ static int mkv_write_tracks(AVFormatContext *s) } if ((pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live) - end_ebml_master_crc32_preliminary(pb, &mkv->tracks_bc, mkv, &mkv->tracks_pos); + end_ebml_master_crc32_preliminary(pb, &mkv->tracks_bc, mkv, + MATROSKA_ID_TRACKS, &mkv->tracks_pos); else - end_ebml_master_crc32(pb, &mkv->tracks_bc, mkv); + end_ebml_master_crc32(pb, &mkv->tracks_bc, mkv, MATROSKA_ID_TRACKS); return 0; } @@ -1486,7 +1488,7 @@ static int mkv_write_chapters(AVFormatContext *s) ret = mkv_add_seekhead_entry(mkv->seekhead, MATROSKA_ID_CHAPTERS, avio_tell(pb)); if (ret < 0) return ret; - ret = start_ebml_master_crc32(pb, &dyn_cp, mkv, MATROSKA_ID_CHAPTERS); + ret = start_ebml_master_crc32(&dyn_cp, mkv); if (ret < 0) return ret; editionentry = start_ebml_master(dyn_cp, MATROSKA_ID_EDITIONENTRY, 0); @@ -1524,7 +1526,7 @@ static int mkv_write_chapters(AVFormatContext *s) end_ebml_master(dyn_cp, chapteratom); } end_ebml_master(dyn_cp, editionentry); - end_ebml_master_crc32(pb, &dyn_cp, mkv); + end_ebml_master_crc32(pb, &dyn_cp, mkv, MATROSKA_ID_CHAPTERS); mkv->wrote_chapters = 1; return 0; @@ -1576,7 +1578,7 @@ static int mkv_write_tag_targets(AVFormatContext *s, uint32_t elementid, ret = mkv_add_seekhead_entry(mkv->seekhead, MATROSKA_ID_TAGS, avio_tell(s->pb)); if (ret < 0) return ret; - start_ebml_master_crc32(s->pb, &mkv->tags_bc, mkv, MATROSKA_ID_TAGS); + start_ebml_master_crc32(&mkv->tags_bc, mkv); } pb = mkv->tags_bc; @@ -1716,9 +1718,10 @@ static int mkv_write_tags(AVFormatContext *s) if (mkv->tags_bc) { if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live) - end_ebml_master_crc32_preliminary(s->pb, &mkv->tags_bc, mkv, &mkv->tags_pos); + end_ebml_master_crc32_preliminary(s->pb, &mkv->tags_bc, mkv, + MATROSKA_ID_TAGS, &mkv->tags_pos); else - end_ebml_master_crc32(s->pb, &mkv->tags_bc, mkv); + end_ebml_master_crc32(s->pb, &mkv->tags_bc, mkv, MATROSKA_ID_TAGS); } return 0; } @@ -1742,7 +1745,7 @@ static int mkv_write_attachments(AVFormatContext *s) ret = mkv_add_seekhead_entry(mkv->seekhead, MATROSKA_ID_ATTACHMENTS, avio_tell(pb)); if (ret < 0) return ret; - ret = start_ebml_master_crc32(pb, &dyn_cp, mkv, MATROSKA_ID_ATTACHMENTS); + ret = start_ebml_master_crc32(&dyn_cp, mkv); if (ret < 0) return ret; for (i = 0; i < s->nb_streams; i++) { @@ -1815,7 +1818,7 @@ static int mkv_write_attachments(AVFormatContext *s) mkv->attachments->entries[mkv->attachments->num_entries].stream_idx = i; mkv->attachments->entries[mkv->attachments->num_entries++].fileuid = fileuid; } - end_ebml_master_crc32(pb, &dyn_cp, mkv); + end_ebml_master_crc32(pb, &dyn_cp, mkv, MATROSKA_ID_ATTACHMENTS); return 0; } @@ -1901,7 +1904,7 @@ static int mkv_write_header(AVFormatContext *s) ret = mkv_add_seekhead_entry(mkv->seekhead, MATROSKA_ID_INFO, avio_tell(pb)); if (ret < 0) goto fail; - ret = start_ebml_master_crc32(pb, &mkv->info_bc, mkv, MATROSKA_ID_INFO); + ret = start_ebml_master_crc32(&mkv->info_bc, mkv); if (ret < 0) return ret; pb = mkv->info_bc; @@ -1960,9 +1963,10 @@ static int mkv_write_header(AVFormatContext *s) } } if ((s->pb->seekable & AVIO_SEEKABLE_NORMAL) && !mkv->is_live) - end_ebml_master_crc32_preliminary(s->pb, &mkv->info_bc, mkv, &mkv->info_pos); + end_ebml_master_crc32_preliminary(s->pb, &mkv->info_bc, mkv, + MATROSKA_ID_INFO, &mkv->info_pos); else - end_ebml_master_crc32(s->pb, &mkv->info_bc, mkv); + end_ebml_master_crc32(s->pb, &mkv->info_bc, mkv, MATROSKA_ID_INFO); pb = s->pb; // initialize stream_duration fields @@ -2258,7 +2262,7 @@ static void mkv_start_new_cluster(AVFormatContext *s, AVPacket *pkt) { MatroskaMuxContext *mkv = s->priv_data; - end_ebml_master_crc32(s->pb, &mkv->cluster_bc, mkv); + end_ebml_master_crc32(s->pb, &mkv->cluster_bc, mkv, MATROSKA_ID_CLUSTER); mkv->cluster_pos = -1; av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64 " bytes, " @@ -2403,7 +2407,7 @@ static int mkv_write_packet_internal(AVFormatContext *s, AVPacket *pkt, int add_ if (mkv->cluster_pos == -1) { mkv->cluster_pos = avio_tell(s->pb); - ret = start_ebml_master_crc32(s->pb, &mkv->cluster_bc, mkv, MATROSKA_ID_CLUSTER); + ret = start_ebml_master_crc32(&mkv->cluster_bc, mkv); if (ret < 0) return ret; put_ebml_uint(mkv->cluster_bc, MATROSKA_ID_CLUSTERTIMECODE, FFMAX(0, ts)); @@ -2539,7 +2543,8 @@ static int mkv_write_flush_packet(AVFormatContext *s, AVPacket *pkt) if (!pkt) { if (mkv->cluster_pos != -1) { - end_ebml_master_crc32(s->pb, &mkv->cluster_bc, mkv); + end_ebml_master_crc32(s->pb, &mkv->cluster_bc, + mkv, MATROSKA_ID_CLUSTER); mkv->cluster_pos = -1; av_log(s, AV_LOG_DEBUG, "Flushing cluster at offset %" PRIu64 " bytes\n", @@ -2570,7 +2575,7 @@ static int mkv_write_trailer(AVFormatContext *s) } if (mkv->cluster_bc) { - end_ebml_master_crc32(pb, &mkv->cluster_bc, mkv); + end_ebml_master_crc32(pb, &mkv->cluster_bc, mkv, MATROSKA_ID_CLUSTER); } ret = mkv_write_chapters(s); @@ -2619,11 +2624,11 @@ static int mkv_write_trailer(AVFormatContext *s) avio_seek(mkv->info_bc, mkv->duration_offset, SEEK_SET); put_ebml_float(mkv->info_bc, MATROSKA_ID_DURATION, mkv->duration); avio_seek(pb, mkv->info_pos, SEEK_SET); - end_ebml_master_crc32(pb, &mkv->info_bc, mkv); + end_ebml_master_crc32(pb, &mkv->info_bc, mkv, MATROSKA_ID_INFO); // write tracks master avio_seek(pb, mkv->tracks_pos, SEEK_SET); - end_ebml_master_crc32(pb, &mkv->tracks_bc, mkv); + end_ebml_master_crc32(pb, &mkv->tracks_bc, mkv, MATROSKA_ID_TRACKS); // update stream durations if (!mkv->is_live && mkv->stream_durations) { @@ -2652,7 +2657,7 @@ static int mkv_write_trailer(AVFormatContext *s) } if (mkv->tags_bc && !mkv->is_live) { avio_seek(pb, mkv->tags_pos, SEEK_SET); - end_ebml_master_crc32(pb, &mkv->tags_bc, mkv); + end_ebml_master_crc32(pb, &mkv->tags_bc, mkv, MATROSKA_ID_TAGS); } avio_seek(pb, currentpos, SEEK_SET); _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".