void av_read_frame_flush(AVFormatContext *s);
+/**
+ * Probes a bytestream to determine the input format. Each time a
+ * probe returns with a score that is too low, the probe buffer size
+ * is increased and another attempt is made. When the maximum probe
+ * size is reached, the input format with the highest score is
+ * returned.
+ *
+ * @param pb the bytestream to probe, it may be closed and opened again
+ * @param fmt the input format is put here
+ * @param filename the filename of the stream
+ * @param logctx the log context
+ * @param offset the offset within the bytestream to probe from
+ * @param max_probe_size the maximum probe buffer size (zero for default)
+ * @return 0 if OK, a negative value corresponding to an AVERROR(xxx)
+ * code otherwise
+ */
+int ff_probe_input_buffer(ByteIOContext **pb, AVInputFormat **fmt,
+ const char *filename, void *logctx,
+ unsigned int offset, unsigned int max_probe_size);
+
#endif /* AVFORMAT_INTERNAL_H */
#define PROBE_BUF_MIN 2048
#define PROBE_BUF_MAX (1<<20)
+int ff_probe_input_buffer(ByteIOContext **pb, AVInputFormat **fmt,
+ const char *filename, void *logctx,
+ unsigned int offset, unsigned int max_probe_size)
+{
+ AVProbeData pd = { filename ? filename : "", NULL, -offset };
+ unsigned char *buf = NULL;
+ int probe_size;
+
+ if (!max_probe_size) {
+ max_probe_size = PROBE_BUF_MAX;
+ } else if (max_probe_size > PROBE_BUF_MAX) {
+ max_probe_size = PROBE_BUF_MAX;
+ } else if (max_probe_size < PROBE_BUF_MIN) {
+ return AVERROR(EINVAL);
+ }
+
+ if (offset >= max_probe_size) {
+ return AVERROR(EINVAL);
+ }
+
+ for(probe_size= PROBE_BUF_MIN; probe_size<=max_probe_size && !*fmt; probe_size<<=1){
+ int ret, score = probe_size < max_probe_size ? AVPROBE_SCORE_MAX/4 : 0;
+ int buf_offset = (probe_size == PROBE_BUF_MIN) ? 0 : probe_size>>1;
+
+ if (probe_size < offset) {
+ continue;
+ }
+
+ /* read probe data */
+ buf = av_realloc(buf, probe_size + AVPROBE_PADDING_SIZE);
+ if ((ret = get_buffer(*pb, buf + buf_offset, probe_size - buf_offset)) < 0) {
+ av_free(buf);
+ return ret;
+ }
+ pd.buf_size += ret;
+ pd.buf = &buf[offset];
+
+ memset(pd.buf + pd.buf_size, 0, AVPROBE_PADDING_SIZE);
+
+ /* guess file format */
+ *fmt = av_probe_input_format2(&pd, 1, &score);
+ if(*fmt){
+ if(score <= AVPROBE_SCORE_MAX/4){ //this can only be true in the last iteration
+ av_log(logctx, AV_LOG_WARNING, "Format detected only with low score of %d, misdetection possible!\n", score);
+ }else
+ av_log(logctx, AV_LOG_DEBUG, "Probed with size=%d and score=%d\n", probe_size, score);
+ }
+ }
+
+ av_free(buf);
+ if (url_fseek(*pb, 0, SEEK_SET) < 0) {
+ url_fclose(*pb);
+ if (url_fopen(pb, filename, URL_RDONLY) < 0)
+ return AVERROR(EIO);
+ }
+
+ return 0;
+}
+
int av_open_input_file(AVFormatContext **ic_ptr, const char *filename,
AVInputFormat *fmt,
int buf_size,
AVFormatParameters *ap)
{
- int err, probe_size;
+ int err;
AVProbeData probe_data, *pd = &probe_data;
ByteIOContext *pb = NULL;
void *logctx= ap && ap->prealloced_context ? *ic_ptr : NULL;
if (buf_size > 0) {
url_setbufsize(pb, buf_size);
}
-
- for(probe_size= PROBE_BUF_MIN; probe_size<=PROBE_BUF_MAX && !fmt; probe_size<<=1){
- int score= probe_size < PROBE_BUF_MAX ? AVPROBE_SCORE_MAX/4 : 0;
- /* read probe data */
- pd->buf= av_realloc(pd->buf, probe_size + AVPROBE_PADDING_SIZE);
- pd->buf_size = get_buffer(pb, pd->buf, probe_size);
-
- if ((int)pd->buf_size < 0) {
- err = pd->buf_size;
- goto fail;
- }
-
- memset(pd->buf+pd->buf_size, 0, AVPROBE_PADDING_SIZE);
- if (url_fseek(pb, 0, SEEK_SET) < 0) {
- url_fclose(pb);
- if (url_fopen(&pb, filename, URL_RDONLY) < 0) {
- pb = NULL;
- err = AVERROR(EIO);
- goto fail;
- }
- }
- /* guess file format */
- fmt = av_probe_input_format2(pd, 1, &score);
- if(fmt){
- if(score <= AVPROBE_SCORE_MAX/4){ //this can only be true in the last iteration
- av_log(logctx, AV_LOG_WARNING, "Format detected only with low score of %d, misdetection possible!\n", score);
- }else
- av_log(logctx, AV_LOG_DEBUG, "Probed with size=%d and score=%d\n", probe_size, score);
- }
+ if ((err = ff_probe_input_buffer(&pb, &fmt, filename, logctx, 0, 0)) < 0) {
+ goto fail;
}
- av_freep(&pd->buf);
}
/* if still no format found, error */