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lavf: simplify handling of offset in av_probe_input_buuffer()

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This commit is contained in:
Anton Khirnov 2014-01-13 11:55:18 +01:00
parent 99e2012523
commit c1868e7ee7
1 changed files with 4 additions and 6 deletions
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10
libavformat/utils.c
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@ -242,7 +242,7 @@ int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
const char *filename, void *logctx, const char *filename, void *logctx,
unsigned int offset, unsigned int max_probe_size) unsigned int offset, unsigned int max_probe_size)
{ {
AVProbeData pd = { filename ? filename : "", NULL, -offset }; AVProbeData pd = { filename ? filename : "" };
unsigned char *buf = NULL; unsigned char *buf = NULL;
int ret = 0, probe_size; int ret = 0, probe_size;
@ -257,16 +257,14 @@ int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
if (offset >= max_probe_size) { if (offset >= max_probe_size) {
return AVERROR(EINVAL); return AVERROR(EINVAL);
} }
avio_skip(pb, offset);
max_probe_size -= offset;
for(probe_size= PROBE_BUF_MIN; probe_size<=max_probe_size && !*fmt; for(probe_size= PROBE_BUF_MIN; probe_size<=max_probe_size && !*fmt;
probe_size = FFMIN(probe_size<<1, FFMAX(max_probe_size, probe_size+1))) { probe_size = FFMIN(probe_size<<1, FFMAX(max_probe_size, probe_size+1))) {
int score = probe_size < max_probe_size ? AVPROBE_SCORE_MAX/4 : 0; int score = probe_size < max_probe_size ? AVPROBE_SCORE_MAX/4 : 0;
int buf_offset = (probe_size == PROBE_BUF_MIN) ? 0 : probe_size>>1; int buf_offset = (probe_size == PROBE_BUF_MIN) ? 0 : probe_size>>1;
if (probe_size < offset) {
continue;
}
/* read probe data */ /* read probe data */
if ((ret = av_reallocp(&buf, probe_size + AVPROBE_PADDING_SIZE)) < 0) if ((ret = av_reallocp(&buf, probe_size + AVPROBE_PADDING_SIZE)) < 0)
return ret; return ret;
@ -280,7 +278,7 @@ int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
ret = 0; /* error was end of file, nothing read */ ret = 0; /* error was end of file, nothing read */
} }
pd.buf_size += ret; pd.buf_size += ret;
pd.buf = &buf[offset]; pd.buf = buf;
memset(pd.buf + pd.buf_size, 0, AVPROBE_PADDING_SIZE); memset(pd.buf + pd.buf_size, 0, AVPROBE_PADDING_SIZE);