Chiebot-Mirror
/
FFmpeg
mirror of https://github.com/FFmpeg/FFmpeg.git
8
0
Fork 0
Code Issues Projects Releases Wiki Activity

matroskadec: use generic parser to parse seekhead

Browse Source 
Originally committed as revision 14564 to svn://svn.ffmpeg.org/ffmpeg/trunk
pull/126/head
Aurelien Jacobs 17 years ago
parent 8ecdab8f5a
commit 13b350a3a4
1 changed files with 47 additions and 113 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 160
      libavformat/matroskadec.c

160
libavformat/matroskadec.c
Unescape View File

@ -163,6 +163,11 @@ typedef struct {
EbmlList pos;
} MatroskaIndex;
typedef struct {
uint64_t id;
uint64_t pos;
} MatroskaSeekhead;
typedef struct MatroskaLevel {
uint64_t start;
uint64_t length;
@ -184,6 +189,7 @@ typedef struct MatroskaDemuxContext {
EbmlList attachments;
EbmlList chapters;
EbmlList index;
EbmlList seekhead;
/* num_streams is the number of streams that av_new_stream() was called
* for ( = that are available to the calling program). */
@ -388,6 +394,19 @@ static EbmlSyntax matroska_tags[] = {
{ 0 }
};
static EbmlSyntax matroska_seekhead_entry[] = {
{ MATROSKA_ID_SEEKID, EBML_UINT, 0, offsetof(MatroskaSeekhead,id) },
{ MATROSKA_ID_SEEKPOSITION, EBML_UINT, 0, offsetof(MatroskaSeekhead,pos), {.u=-1} },
{ EBML_ID_VOID, EBML_NONE },
{ 0 }
};
static EbmlSyntax matroska_seekhead[] = {
{ MATROSKA_ID_SEEKENTRY, EBML_NEST, sizeof(MatroskaSeekhead), offsetof(MatroskaDemuxContext,seekhead), {.n=matroska_seekhead_entry} },
{ EBML_ID_VOID, EBML_NONE },
{ 0 }
};
/*
* The first few functions handle EBML file parsing. The rest
* is the document interpretation. Matroska really just is a
@ -1316,86 +1335,32 @@ matroska_parse_metadata (MatroskaDemuxContext *matroska)
static int
matroska_parse_seekhead (MatroskaDemuxContext *matroska)
{
int res = 0;
uint32_t id;
av_log(matroska->ctx, AV_LOG_DEBUG, "parsing seekhead...\n");
while (res == 0) {
if (!(id = ebml_peek_id(matroska, &matroska->level_up))) {
res = AVERROR(EIO);
break;
} else if (matroska->level_up) {
matroska->level_up--;
break;
}
switch (id) {
case MATROSKA_ID_SEEKENTRY: {
uint32_t seek_id = 0, peek_id_cache = 0;
uint64_t seek_pos = (uint64_t) -1, t;
int dummy_level = 0;
if ((res = ebml_read_master(matroska, &id)) < 0)
break;
while (res == 0) {
if (!(id = ebml_peek_id(matroska, &matroska->level_up))) {
res = AVERROR(EIO);
break;
} else if (matroska->level_up) {
matroska->level_up--;
break;
}
switch (id) {
case MATROSKA_ID_SEEKID:
res = ebml_read_uint(matroska, &id, &t);
seek_id = t;
break;
case MATROSKA_ID_SEEKPOSITION:
res = ebml_read_uint(matroska, &id, &seek_pos);
break;
default:
av_log(matroska->ctx, AV_LOG_INFO,
"Unknown seekhead ID 0x%x\n", id);
/* fall-through */
case EBML_ID_VOID:
res = ebml_read_skip(matroska);
break;
}
if (matroska->level_up) {
matroska->level_up--;
break;
}
}
if (!seek_id || seek_pos == (uint64_t) -1) {
av_log(matroska->ctx, AV_LOG_INFO,
"Incomplete seekhead entry (0x%x/%"PRIu64")\n",
seek_id, seek_pos);
break;
}
return ebml_parse(matroska, matroska_seekhead, matroska, MATROSKA_ID_SEEKHEAD, 0);
}
switch (seek_id) {
case MATROSKA_ID_CUES:
case MATROSKA_ID_TAGS: {
uint32_t level_up = matroska->level_up;
offset_t before_pos;
MatroskaLevel level;
static void
matroska_execute_seekhead(MatroskaDemuxContext *matroska)
{
EbmlList *seekhead_list = &matroska->seekhead;
MatroskaSeekhead *seekhead = seekhead_list->elem;
uint32_t peek_id_cache = matroska->peek_id;
uint32_t level_up = matroska->level_up;
offset_t before_pos = url_ftell(matroska->ctx->pb);
int dummy_level = 0;
MatroskaLevel level;
uint32_t id;
int i, res;
/* remember the peeked ID and the current position */
peek_id_cache = matroska->peek_id;
before_pos = url_ftell(matroska->ctx->pb);
for (i=0; i<seekhead_list->nb_elem; i++) {
if (seekhead[i].pos <= before_pos
|| seekhead[i].id == MATROSKA_ID_SEEKHEAD
|| seekhead[i].id == MATROSKA_ID_CLUSTER)
continue;
/* seek */
if ((res = ebml_read_seek(matroska, seek_pos +
matroska->segment_start)) < 0)
goto finish;
if (ebml_read_seek(matroska,
seekhead[i].pos+matroska->segment_start) < 0)
continue;
/* we don't want to lose our seekhead level, so we add
* a dummy. This is a crude hack. */
@ -1403,7 +1368,7 @@ matroska_parse_seekhead (MatroskaDemuxContext *matroska)
av_log(matroska->ctx, AV_LOG_INFO,
"Max EBML element depth (%d) reached, "
"cannot parse further.\n", EBML_MAX_DEPTH);
return AVERROR_UNKNOWN;
break;
}
level.start = 0;
@ -1416,11 +1381,11 @@ matroska_parse_seekhead (MatroskaDemuxContext *matroska)
if (!(id = ebml_peek_id (matroska,
&matroska->level_up)))
goto finish;
if (id != seek_id) {
if (id != seekhead[i].id) {
av_log(matroska->ctx, AV_LOG_INFO,
"We looked for ID=0x%x but got "
"ID=0x%x (pos=%"PRIu64")",
seek_id, id, seek_pos +
(int)seekhead[i].id, id, seekhead[i].pos +
matroska->segment_start);
goto finish;
}
@ -1451,42 +1416,12 @@ matroska_parse_seekhead (MatroskaDemuxContext *matroska)
if (length == (uint64_t)-1)
break;
}
}
/* seek back */
if ((res = ebml_read_seek(matroska, before_pos)) < 0)
return res;
ebml_read_seek(matroska, before_pos);
matroska->peek_id = peek_id_cache;
matroska->level_up = level_up;
break;
}
default:
av_log(matroska->ctx, AV_LOG_INFO,
"Ignoring seekhead entry for ID=0x%x\n",
seek_id);
break;
}
break;
}
default:
av_log(matroska->ctx, AV_LOG_INFO,
"Unknown seekhead ID 0x%x\n", id);
/* fall-through */
case EBML_ID_VOID:
res = ebml_read_skip(matroska);
break;
}
if (matroska->level_up) {
matroska->level_up--;
break;
}
}
return res;
}
static int
@ -1667,8 +1602,6 @@ matroska_read_header (AVFormatContext *s,
/* file index (if seekable, seek to Cues/Tags to parse it) */
case MATROSKA_ID_SEEKHEAD: {
if ((res = ebml_read_master(matroska, &id)) < 0)
break;
res = matroska_parse_seekhead(matroska);
break;
}
@ -1705,6 +1638,7 @@ matroska_read_header (AVFormatContext *s,
break;
}
}
matroska_execute_seekhead(matroska);
/* Have we found a cluster? */
if (ebml_peek_id(matroska, NULL) == MATROSKA_ID_CLUSTER) {

Write Preview
Loading…
Cancel
Save