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Cleanup flv keyframe index reading and add some saftey checks. 

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2011-04-01 13:33:51 +02:00
parent 676d380f2a
commit 0c4d4a9355
1 changed files with 22 additions and 27 deletions
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49
libavformat/flvdec.c
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@ -130,54 +130,49 @@ static int amf_get_string(AVIOContext *ioc, char *buffer, int buffsize) {
}
static int parse_keyframes_index(AVFormatContext *s, AVIOContext *ioc, AVStream *vstream, int64_t max_pos) {
unsigned int arraylen = 0, timeslen = 0, fileposlen = 0, i;
double num_val;
unsigned int timeslen = 0, fileposlen = 0, i;
char str_val[256];
int64_t *times = NULL;
int64_t *filepositions = NULL;
int ret = 0;
while (avio_tell(ioc) < max_pos - 2 && amf_get_string(ioc, str_val, sizeof(str_val)) > 0) {
int64_t* current_array;
int64_t** current_array;
unsigned int arraylen;
// Expect array object in context
if (avio_r8(ioc) != AMF_DATA_TYPE_ARRAY)
break;
arraylen = avio_rb32(ioc);
/*
* Expect only 'times' or 'filepositions' sub-arrays in other case refuse to use such metadata
* for indexing
*/
if (!strcmp(KEYFRAMES_TIMESTAMP_TAG, str_val) && !times) {
if (!(times = av_mallocz(sizeof(*times) * arraylen))) {
ret = AVERROR(ENOMEM);
goto finish;
}
timeslen = arraylen;
current_array = times;
} else if (!strcmp(KEYFRAMES_BYTEOFFSET_TAG, str_val) && !filepositions) {
if (!(filepositions = av_mallocz(sizeof(*filepositions) * arraylen))) {
ret = AVERROR(ENOMEM);
goto finish;
}
fileposlen = arraylen;
current_array = filepositions;
} else // unexpected metatag inside keyframes, will not use such metadata for indexing
if(arraylen>>28)
break;
if (!strcmp(KEYFRAMES_TIMESTAMP_TAG , str_val) && !times){
current_array= &times;
timeslen= arraylen;
}else if (!strcmp(KEYFRAMES_BYTEOFFSET_TAG, str_val) && !filepositions){
current_array= &filepositions;
fileposlen= arraylen;
}else // unexpected metatag inside keyframes, will not use such metadata for indexing
break;
if (!(*current_array = av_mallocz(sizeof(**current_array) * arraylen))) {
ret = AVERROR(ENOMEM);
goto finish;
}
for (i = 0; i < arraylen && avio_tell(ioc) < max_pos - 1; i++) {
if (avio_r8(ioc) != AMF_DATA_TYPE_NUMBER)
goto finish;
num_val = av_int2dbl(avio_rb64(ioc));
current_array[i] = num_val;
current_array[0][i] = av_int2dbl(avio_rb64(ioc));
}
}
if (timeslen == fileposlen)
for(i = 0; i < arraylen; i++)
if (timeslen == fileposlen) {
for(i = 0; i < timeslen; i++)
av_add_index_entry(vstream, filepositions[i], times[i]*1000, 0, 0, AVINDEX_KEYFRAME);
else
} else
av_log(s, AV_LOG_WARNING, "Invalid keyframes object, skipping.\n");
finish: