avformat/mov: Stash mfra size if we're reading it anyway

This also changes a check for mfra_size from < 0 to == 0, since
it was always wrong, as avio_rb32 returns an unsigned integer.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>
This commit is contained in:
Derek Buitenhuis 2020-09-01 15:42:17 +01:00
parent 97fa669a6f
commit 2c0d6ac9ae

View File

@ -7499,22 +7499,22 @@ static int mov_read_mfra(MOVContext *c, AVIOContext *f)
int64_t stream_size = avio_size(f);
int64_t original_pos = avio_tell(f);
int64_t seek_ret;
int32_t mfra_size;
int ret = -1;
if ((seek_ret = avio_seek(f, stream_size - 4, SEEK_SET)) < 0) {
ret = seek_ret;
goto fail;
}
mfra_size = avio_rb32(f);
if (mfra_size < 0 || mfra_size > stream_size) {
c->mfra_size = avio_rb32(f);
c->have_read_mfra_size = 1;
if (!c->mfra_size || c->mfra_size > stream_size) {
av_log(c->fc, AV_LOG_DEBUG, "doesn't look like mfra (unreasonable size)\n");
goto fail;
}
if ((seek_ret = avio_seek(f, -mfra_size, SEEK_CUR)) < 0) {
if ((seek_ret = avio_seek(f, -((int64_t) c->mfra_size), SEEK_CUR)) < 0) {
ret = seek_ret;
goto fail;
}
if (avio_rb32(f) != mfra_size) {
if (avio_rb32(f) != c->mfra_size) {
av_log(c->fc, AV_LOG_DEBUG, "doesn't look like mfra (size mismatch)\n");
goto fail;
}