+/**
+ * Parse interval specification, according to the format:
+ * INTERVAL ::= [START|+START_OFFSET][%[END|+END_OFFSET]]
+ * INTERVALS ::= INTERVAL[,INTERVALS]
+*/
+static int parse_read_interval(const char *interval_spec,
+ ReadInterval *interval)
+{
+ int ret = 0;
+ char *next, *p, *spec = av_strdup(interval_spec);
+ if (!spec)
+ return AVERROR(ENOMEM);
+
+ if (!*spec) {
+ av_log(NULL, AV_LOG_ERROR, "Invalid empty interval specification\n");
+ ret = AVERROR(EINVAL);
+ goto end;
+ }
+
+ p = spec;
+ next = strchr(spec, '%');
+ if (next)
+ *next++ = 0;
+
+ /* parse first part */
+ if (*p) {
+ interval->has_start = 1;
+
+ if (*p == '+') {
+ interval->start_is_offset = 1;
+ p++;
+ } else {
+ interval->start_is_offset = 0;
+ }
+
+ ret = av_parse_time(&interval->start, p, 1);
+ if (ret < 0) {
+ av_log(NULL, AV_LOG_ERROR, "Invalid interval start specification '%s'\n", p);
+ goto end;
+ }
+ } else {
+ interval->has_start = 0;
+ }
+
+ /* parse second part */
+ p = next;
+ if (p && *p) {
+ int64_t us;
+ interval->has_end = 1;
+
+ if (*p == '+') {
+ interval->end_is_offset = 1;
+ p++;
+ } else {
+ interval->end_is_offset = 0;
+ }
+
+ if (interval->end_is_offset && *p == '#') {
+ long long int lli;
+ char *tail;
+ interval->duration_frames = 1;
+ p++;
+ lli = strtoll(p, &tail, 10);
+ if (*tail || lli < 0) {
+ av_log(NULL, AV_LOG_ERROR,
+ "Invalid or negative value '%s' for duration number of frames\n", p);
+ goto end;
+ }
+ interval->end = lli;
+ } else {
+ ret = av_parse_time(&us, p, 1);
+ if (ret < 0) {
+ av_log(NULL, AV_LOG_ERROR, "Invalid interval end/duration specification '%s'\n", p);
+ goto end;
+ }
+ interval->end = us;
+ }
+ } else {
+ interval->has_end = 0;
+ }
+
+end:
+ av_free(spec);
+ return ret;
+}
+
+static int parse_read_intervals(const char *intervals_spec)
+{
+ int ret, n, i;
+ char *p, *spec = av_strdup(intervals_spec);
+ if (!spec)
+ return AVERROR(ENOMEM);
+
+ /* preparse specification, get number of intervals */
+ for (n = 0, p = spec; *p; p++)
+ if (*p == ',')
+ n++;
+ n++;
+
+ read_intervals = av_malloc(n * sizeof(*read_intervals));
+ if (!read_intervals) {
+ ret = AVERROR(ENOMEM);
+ goto end;
+ }
+ read_intervals_nb = n;
+
+ /* parse intervals */
+ p = spec;
+ for (i = 0; i < n; i++) {
+ char *next = strchr(p, ',');
+ if (next)
+ *next++ = 0;
+
+ read_intervals[i].id = i;
+ ret = parse_read_interval(p, &read_intervals[i]);
+ if (ret < 0) {
+ av_log(NULL, AV_LOG_ERROR, "Error parsing read interval #%d '%s'\n",
+ i, p);
+ goto end;
+ }
+ av_log(NULL, AV_LOG_VERBOSE, "Parsed log interval ");
+ log_read_interval(&read_intervals[i], NULL, AV_LOG_VERBOSE);
+ p = next;
+ av_assert0(i <= read_intervals_nb);
+ }
+ av_assert0(i == read_intervals_nb);
+
+end:
+ av_free(spec);
+ return ret;
+}
+
+static int opt_read_intervals(void *optctx, const char *opt, const char *arg)
+{
+ return parse_read_intervals(arg);
+}
+