[FFmpeg-soc] [soc]: r279 - matroska/matroskaenc.c
conrad
subversion at mplayerhq.hu
Mon Jun 25 02:24:04 CEST 2007
Author: conrad
Date: Mon Jun 25 02:24:04 2007
New Revision: 279
Log:
Write the Seek Head element
Modified:
matroska/matroskaenc.c
Modified: matroska/matroskaenc.c
==============================================================================
--- matroska/matroskaenc.c (original)
+++ matroska/matroskaenc.c Mon Jun 25 02:24:04 2007
@@ -24,12 +24,29 @@
#include "xiph.h"
#include "matroska.h"
+typedef struct mkv_seekhead_entry {
+ unsigned int elementid;
+ uint64_t segmentpos;
+} mkv_seekhead_entry;
+
+typedef struct mkv_seekhead {
+ offset_t filepos;
+ offset_t segment_offset; // the file offset to the beginning of the segment
+ int reserved_size; // -1 if appending to file
+ int max_entries;
+ mkv_seekhead_entry *entries;
+ int num_entries;
+} mkv_seekhead;
+
typedef struct MatroskaMuxContext {
offset_t segment;
+ offset_t segment_offset;
offset_t cluster;
uint64_t cluster_pts;
offset_t duration_offset;
uint64_t duration;
+ mkv_seekhead *main_seekhead;
+ mkv_seekhead *cluster_seekhead;
} MatroskaMuxContext;
static void put_ebml_id(ByteIOContext *pb, unsigned int id)
@@ -43,6 +60,17 @@ static void put_ebml_id(ByteIOContext *p
put_byte(pb, id);
}
+static int ebml_id_size(unsigned int id)
+{
+ if (id >= 0x3fffff)
+ return 4;
+ if (id >= 0x7fff)
+ return 3;
+ if (id >= 0xff)
+ return 2;
+ return 1;
+}
+
// XXX: test this thoroughly and get rid of minbytes hack (currently needed to
// use up all of the space reserved in start_ebml_master)
static void put_ebml_size(ByteIOContext *pb, uint64_t size, int minbytes)
@@ -128,6 +156,91 @@ static void end_ebml_master(ByteIOContex
url_fseek(pb, pos, SEEK_SET);
}
+// initializes a mkv_seekhead element to be ready to index level 1 matroska elements
+// if numelements is greater than 0, it reserves enough space for that many elements
+// at the current file position and writes the seekhead there, otherwise the seekhead
+// will be appended to the file when end_mkv_seekhead() is called
+static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, offset_t segment_offset, int numelements)
+{
+ mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
+ if (new_seekhead == NULL)
+ return NULL;
+
+ new_seekhead->segment_offset = segment_offset;
+
+ if (numelements > 0) {
+ new_seekhead->filepos = url_ftell(pb);
+ // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID and size,
+ // and 3 bytes to guarantee that an EBML void element will fit afterwards
+ // XXX: 28 bytes right now because begin_ebml_master() reserves more than necessary
+ new_seekhead->reserved_size = numelements * 28 + 13;
+ new_seekhead->max_entries = numelements;
+ put_ebml_void(pb, new_seekhead->reserved_size);
+ }
+ return new_seekhead;
+}
+
+static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
+{
+ mkv_seekhead_entry *entries = seekhead->entries;
+ int new_entry = seekhead->num_entries;
+
+ // don't store more elements than we reserved space for
+ if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
+ return -1;
+
+ entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
+ if (entries == NULL)
+ return -1;
+
+ entries[new_entry].elementid = elementid;
+ entries[new_entry].segmentpos = filepos - seekhead->segment_offset;
+
+ seekhead->entries = entries;
+ seekhead->num_entries++;
+
+ return 0;
+}
+
+// returns the file offset where the seekhead was written and frees the seekhead
+static offset_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
+{
+ offset_t metaseek, seekentry, currentpos;
+ int i;
+
+ currentpos = url_ftell(pb);
+
+ if (seekhead->reserved_size > 0)
+ url_fseek(pb, seekhead->filepos, SEEK_SET);
+
+ metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD);
+ for (i = 0; i < seekhead->num_entries; i++) {
+ mkv_seekhead_entry *entry = &seekhead->entries[i];
+
+ seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY);
+
+ put_ebml_id(pb, MATROSKA_ID_SEEKID);
+ put_ebml_size(pb, ebml_id_size(entry->elementid), 0);
+ put_ebml_id(pb, entry->elementid);
+
+ put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
+ end_ebml_master(pb, seekentry);
+ }
+ end_ebml_master(pb, metaseek);
+
+ if (seekhead->reserved_size > 0) {
+ uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
+ put_ebml_void(pb, remaining);
+ url_fseek(pb, currentpos, SEEK_SET);
+
+ currentpos = seekhead->filepos;
+ }
+ av_free(seekhead->entries);
+ av_free(seekhead);
+
+ return currentpos;
+}
+
static int put_xiph_codecpriv(ByteIOContext *pb, AVCodecContext *codec)
{
offset_t codecprivate;
@@ -168,6 +281,9 @@ static int mkv_write_tracks(AVFormatCont
offset_t tracks;
int i, j;
+ if (mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb)) < 0)
+ return -1;
+
tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS);
for (i = 0; i < s->nb_streams; i++) {
AVStream *st = s->streams[i];
@@ -267,6 +383,17 @@ static int mkv_write_header(AVFormatCont
end_ebml_master(pb, ebml_header);
mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT);
+ mkv->segment_offset = url_ftell(pb);
+
+ // we write 2 seek heads - one at the end of the file to point to each cluster, and
+ // one at the beginning to point to all other level one elements (including the seek
+ // head at the end of the file), which isn't more than 10 elements if we only write one
+ // of each other currently defined level 1 element
+ mkv->main_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 10);
+ mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
+
+ if (mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb)) < 0)
+ return -1;
segment_info = start_ebml_master(pb, MATROSKA_ID_INFO);
put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
@@ -287,6 +414,9 @@ static int mkv_write_header(AVFormatCont
if (mkv_write_tracks(s) < 0)
return -1;
+ if (mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb)) < 0)
+ return -1;
+
mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
mkv->cluster_pts = 0;
@@ -303,6 +433,10 @@ static int mkv_write_packet(AVFormatCont
// start a new cluster every 5 MB or 5 sec
if (url_ftell(pb) > mkv->cluster + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
end_ebml_master(pb, mkv->cluster);
+
+ if (mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb)) < 0)
+ return -1;
+
mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
mkv->cluster_pts = pkt->pts;
@@ -323,10 +457,14 @@ static int mkv_write_trailer(AVFormatCon
{
MatroskaMuxContext *mkv = s->priv_data;
ByteIOContext *pb = &s->pb;
- offset_t currentpos;
+ offset_t currentpos, second_seekhead;
end_ebml_master(pb, mkv->cluster);
+ second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
+ mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
+ mkv_write_seekhead(pb, mkv->main_seekhead);
+
// update the duration
currentpos = url_ftell(pb);
url_fseek(pb, mkv->duration_offset, SEEK_SET);
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