lavfi: add internal functions for parsing format arguments

Signed-off-by: Stefano Sabatini <stefano.sabatini-lala@poste.it>

libavfilter/formats.c

@@ -19,6 +19,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/eval.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/audioconvert.h"
 #include "avfilter.h"
@@ -233,3 +234,61 @@ void avfilter_formats_changeref(AVFilterFormats **oldref,
     }
 }
 
+/* internal functions for parsing audio format arguments */
+
+int ff_parse_sample_format(int *ret, const char *arg, void *log_ctx)
+{
+    char *tail;
+    int sfmt = av_get_sample_fmt(arg);
+    if (sfmt == AV_SAMPLE_FMT_NONE) {
+        sfmt = strtol(arg, &tail, 0);
+        if (*tail || (unsigned)sfmt >= AV_SAMPLE_FMT_NB) {
+            av_log(log_ctx, AV_LOG_ERROR, "Invalid sample format '%s'\n", arg);
+            return AVERROR(EINVAL);
+        }
+    }
+    *ret = sfmt;
+    return 0;
+}
+
+int ff_parse_sample_rate(unsigned *ret, const char *arg, void *log_ctx)
+{
+    char *tail;
+    double srate = av_strtod(arg, &tail);
+    if (*tail || srate < 1 || (int)srate != srate) {
+        av_log(log_ctx, AV_LOG_ERROR, "Invalid sample rate '%s'\n", arg);
+        return AVERROR(EINVAL);
+    }
+    *ret = srate;
+    return 0;
+}
+
+int ff_parse_channel_layout(int64_t *ret, const char *arg, void *log_ctx)
+{
+    char *tail;
+    int64_t chlayout = av_get_channel_layout(arg);
+    if (chlayout == 0) {
+        chlayout = strtol(arg, &tail, 10);
+        if (*tail || chlayout == 0) {
+            av_log(log_ctx, AV_LOG_ERROR, "Invalid channel layout '%s'\n", arg);
+            return AVERROR(EINVAL);
+        }
+    }
+    *ret = chlayout;
+    return 0;
+}
+
+int ff_parse_packing_format(int *ret, const char *arg, void *log_ctx)
+{
+    char *tail;
+    int planar = strtol(arg, &tail, 10);
+    if (*tail) {
+        planar = (strcmp(arg, "packed") != 0);
+    } else if (planar != 0 && planar != 1) {
+        av_log(log_ctx, AV_LOG_ERROR, "Invalid packing format '%s'\n", arg);
+        return AVERROR(EINVAL);
+    }
+    *ret = planar;
+    return 0;
+}
+

libavfilter/internal.h

@@ -61,4 +61,46 @@ void ff_avfilter_default_free_buffer(AVFilterBuffer *buf);
 /** Tell is a format is contained in the provided list terminated by -1. */
 int ff_fmt_is_in(int fmt, const int *fmts);
 
+/* Functions to parse audio format arguments */
+
+/**
+ * Parse a sample rate.
+ *
+ * @param ret unsigned integer pointer to where the value should be written
+ * @param arg string to parse
+ * @param log_ctx log context
+ * @return 0 in case of success, a negative AVERROR code on error
+ */
+int ff_parse_sample_rate(unsigned *ret, const char *arg, void *log_ctx);
+
+/**
+ * Parse a sample format name or a corresponding integer representation.
+ *
+ * @param ret integer pointer to where the value should be written
+ * @param arg string to parse
+ * @param log_ctx log context
+ * @return 0 in case of success, a negative AVERROR code on error
+ */
+int ff_parse_sample_format(int *ret, const char *arg, void *log_ctx);
+
+/**
+ * Parse a channel layout or a corresponding integer representation.
+ *
+ * @param ret 64bit integer pointer to where the value should be written.
+ * @param arg string to parse
+ * @param log_ctx log context
+ * @return 0 in case of success, a negative AVERROR code on error
+ */
+int ff_parse_channel_layout(int64_t *ret, const char *arg, void *log_ctx);
+
+/**
+ * Parse a packing format or a corresponding integer representation.
+ *
+ * @param ret integer pointer to where the value should be written
+ * @param arg string to parse
+ * @param log_ctx log context
+ * @return 0 in case of success, a negative AVERROR code on error
+ */
+int ff_parse_packing_format(int *ret, const char *arg, void *log_ctx);
+
 #endif /* AVFILTER_INTERNAL_H */