+static int parse_frames(void *log_ctx, int **frames, int *nb_frames,
+ const char *frames_str)
+{
+ char *p;
+ int i, ret = 0;
+ char *frames_str1 = av_strdup(frames_str);
+ char *saveptr = NULL;
+
+ if (!frames_str1)
+ return AVERROR(ENOMEM);
+
+#define FAIL(err) ret = err; goto end
+
+ *nb_frames = 1;
+ for (p = frames_str1; *p; p++)
+ if (*p == ',')
+ (*nb_frames)++;
+
+ *frames = av_malloc(sizeof(**frames) * *nb_frames);
+ if (!*frames) {
+ av_log(log_ctx, AV_LOG_ERROR, "Could not allocate forced frames array\n");
+ FAIL(AVERROR(ENOMEM));
+ }
+
+ p = frames_str1;
+ for (i = 0; i < *nb_frames; i++) {
+ long int f;
+ char *tailptr;
+ char *fstr = av_strtok(p, ",", &saveptr);
+
+ p = NULL;
+ if (!fstr) {
+ av_log(log_ctx, AV_LOG_ERROR, "Empty frame specification in frame list %s\n",
+ frames_str);
+ FAIL(AVERROR(EINVAL));
+ }
+ f = strtol(fstr, &tailptr, 10);
+ if (*tailptr || f <= 0 || f >= INT_MAX) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Invalid argument '%s', must be a positive integer <= INT64_MAX\n",
+ fstr);
+ FAIL(AVERROR(EINVAL));
+ }
+ (*frames)[i] = f;
+
+ /* check on monotonicity */
+ if (i && (*frames)[i-1] > (*frames)[i]) {
+ av_log(log_ctx, AV_LOG_ERROR,
+ "Specified frame %d is greater than the following frame %d\n",
+ (*frames)[i], (*frames)[i-1]);
+ FAIL(AVERROR(EINVAL));
+ }
+ }
+
+end:
+ av_free(frames_str1);
+ return ret;
+}
+