lavu/opt: factor per-type dispatch out of av_opt_get()

Will be useful in following commits.

1 files changed, 72 insertions, 50 deletions

diff --git a/libavutil/opt.c b/libavutil/opt.c
index d68184c2cc..dac00478ee 100644
--- a/libavutil/opt.c
+++ b/libavutil/opt.c
@@ -844,124 +844,146 @@ static void format_duration(char *buf, size_t size, int64_t d)
         *(--e) = 0;
 }
 
-int av_opt_get(void *obj, const char *name, int search_flags, uint8_t **out_val)
+static int opt_get_elem(const AVOption *o, uint8_t **pbuf, size_t buf_len,
+                        void *dst, int search_flags)
 {
-    void *dst, *target_obj;
-    const AVOption *o = av_opt_find2(obj, name, NULL, 0, search_flags, &target_obj);
-    uint8_t *bin, buf[128];
-    int len, i, ret;
-    int64_t i64;
-
-    if (!o || !target_obj || (o->offset<=0 && o->type != AV_OPT_TYPE_CONST))
-        return AVERROR_OPTION_NOT_FOUND;
-
-    if (o->flags & AV_OPT_FLAG_DEPRECATED)
-        av_log(obj, AV_LOG_WARNING, "The \"%s\" option is deprecated: %s\n", name, o->help);
-
-    dst = (uint8_t *)target_obj + o->offset;
+    int ret;
 
-    buf[0] = 0;
     switch (o->type) {
     case AV_OPT_TYPE_BOOL:
-        ret = snprintf(buf, sizeof(buf), "%s", get_bool_name(*(int *)dst));
+        ret = snprintf(*pbuf, buf_len, "%s", get_bool_name(*(int *)dst));
         break;
     case AV_OPT_TYPE_FLAGS:
-        ret = snprintf(buf, sizeof(buf), "0x%08X", *(int *)dst);
+        ret = snprintf(*pbuf, buf_len, "0x%08X", *(int *)dst);
         break;
     case AV_OPT_TYPE_INT:
-        ret = snprintf(buf, sizeof(buf), "%d", *(int *)dst);
+        ret = snprintf(*pbuf, buf_len, "%d", *(int *)dst);
         break;
     case AV_OPT_TYPE_INT64:
-        ret = snprintf(buf, sizeof(buf), "%"PRId64, *(int64_t *)dst);
+        ret = snprintf(*pbuf, buf_len, "%"PRId64, *(int64_t *)dst);
         break;
     case AV_OPT_TYPE_UINT64:
-        ret = snprintf(buf, sizeof(buf), "%"PRIu64, *(uint64_t *)dst);
+        ret = snprintf(*pbuf, buf_len, "%"PRIu64, *(uint64_t *)dst);
         break;
     case AV_OPT_TYPE_FLOAT:
-        ret = snprintf(buf, sizeof(buf), "%f", *(float *)dst);
+        ret = snprintf(*pbuf, buf_len, "%f", *(float *)dst);
         break;
     case AV_OPT_TYPE_DOUBLE:
-        ret = snprintf(buf, sizeof(buf), "%f", *(double *)dst);
+        ret = snprintf(*pbuf, buf_len, "%f", *(double *)dst);
         break;
     case AV_OPT_TYPE_VIDEO_RATE:
     case AV_OPT_TYPE_RATIONAL:
-        ret = snprintf(buf, sizeof(buf), "%d/%d", ((AVRational *)dst)->num, ((AVRational *)dst)->den);
+        ret = snprintf(*pbuf, buf_len, "%d/%d", ((AVRational *)dst)->num, ((AVRational *)dst)->den);
         break;
     case AV_OPT_TYPE_CONST:
-        ret = snprintf(buf, sizeof(buf), "%"PRId64, o->default_val.i64);
+        ret = snprintf(*pbuf, buf_len, "%"PRId64, o->default_val.i64);
         break;
     case AV_OPT_TYPE_STRING:
         if (*(uint8_t **)dst) {
-            *out_val = av_strdup(*(uint8_t **)dst);
+            *pbuf = av_strdup(*(uint8_t **)dst);
         } else if (search_flags & AV_OPT_ALLOW_NULL) {
-            *out_val = NULL;
+            *pbuf = NULL;
             return 0;
         } else {
-            *out_val = av_strdup("");
+            *pbuf = av_strdup("");
         }
-        return *out_val ? 0 : AVERROR(ENOMEM);
-    case AV_OPT_TYPE_BINARY:
+        return *pbuf ? 0 : AVERROR(ENOMEM);
+    case AV_OPT_TYPE_BINARY: {
+        const uint8_t *bin;
+        int len;
+
         if (!*(uint8_t **)dst && (search_flags & AV_OPT_ALLOW_NULL)) {
-            *out_val = NULL;
+            *pbuf = NULL;
             return 0;
         }
         len = *(int *)(((uint8_t *)dst) + sizeof(uint8_t *));
         if ((uint64_t)len * 2 + 1 > INT_MAX)
             return AVERROR(EINVAL);
-        if (!(*out_val = av_malloc(len * 2 + 1)))
+        if (!(*pbuf = av_malloc(len * 2 + 1)))
             return AVERROR(ENOMEM);
         if (!len) {
-            *out_val[0] = '\0';
+            *pbuf[0] = '\0';
             return 0;
         }
         bin = *(uint8_t **)dst;
-        for (i = 0; i < len; i++)
-            snprintf(*out_val + i * 2, 3, "%02X", bin[i]);
+        for (int i = 0; i < len; i++)
+            snprintf(*pbuf + i * 2, 3, "%02X", bin[i]);
         return 0;
+    }
     case AV_OPT_TYPE_IMAGE_SIZE:
-        ret = snprintf(buf, sizeof(buf), "%dx%d", ((int *)dst)[0], ((int *)dst)[1]);
+        ret = snprintf(*pbuf, buf_len, "%dx%d", ((int *)dst)[0], ((int *)dst)[1]);
         break;
     case AV_OPT_TYPE_PIXEL_FMT:
-        ret = snprintf(buf, sizeof(buf), "%s", (char *)av_x_if_null(av_get_pix_fmt_name(*(enum AVPixelFormat *)dst), "none"));
+        ret = snprintf(*pbuf, buf_len, "%s", (char *)av_x_if_null(av_get_pix_fmt_name(*(enum AVPixelFormat *)dst), "none"));
         break;
     case AV_OPT_TYPE_SAMPLE_FMT:
-        ret = snprintf(buf, sizeof(buf), "%s", (char *)av_x_if_null(av_get_sample_fmt_name(*(enum AVSampleFormat *)dst), "none"));
+        ret = snprintf(*pbuf, buf_len, "%s", (char *)av_x_if_null(av_get_sample_fmt_name(*(enum AVSampleFormat *)dst), "none"));
         break;
-    case AV_OPT_TYPE_DURATION:
-        i64 = *(int64_t *)dst;
-        format_duration(buf, sizeof(buf), i64);
-        ret = strlen(buf); // no overflow possible, checked by an assert
+    case AV_OPT_TYPE_DURATION: {
+        int64_t i64 = *(int64_t *)dst;
+        format_duration(*pbuf, buf_len, i64);
+        ret = strlen(*pbuf); // no overflow possible, checked by an assert
         break;
+    }
     case AV_OPT_TYPE_COLOR:
-        ret = snprintf(buf, sizeof(buf), "0x%02x%02x%02x%02x",
+        ret = snprintf(*pbuf, buf_len, "0x%02x%02x%02x%02x",
                        (int)((uint8_t *)dst)[0], (int)((uint8_t *)dst)[1],
                        (int)((uint8_t *)dst)[2], (int)((uint8_t *)dst)[3]);
         break;
 #if FF_API_OLD_CHANNEL_LAYOUT
 FF_DISABLE_DEPRECATION_WARNINGS
-    case AV_OPT_TYPE_CHANNEL_LAYOUT:
-
-        i64 = *(int64_t *)dst;
-        ret = snprintf(buf, sizeof(buf), "0x%"PRIx64, i64);
+    case AV_OPT_TYPE_CHANNEL_LAYOUT: {
+        int64_t i64 = *(int64_t *)dst;
+        ret = snprintf(*pbuf, buf_len, "0x%"PRIx64, i64);
         break;
+    }
 FF_ENABLE_DEPRECATION_WARNINGS
 #endif
     case AV_OPT_TYPE_CHLAYOUT:
-        ret = av_channel_layout_describe(dst, buf, sizeof(buf));
+        ret = av_channel_layout_describe(dst, *pbuf, buf_len);
         break;
     case AV_OPT_TYPE_DICT:
         if (!*(AVDictionary **)dst && (search_flags & AV_OPT_ALLOW_NULL)) {
-            *out_val = NULL;
+            *pbuf = NULL;
             return 0;
         }
-        return av_dict_get_string(*(AVDictionary **)dst, (char **)out_val, '=', ':');
+        return av_dict_get_string(*(AVDictionary **)dst, (char **)pbuf, '=', ':');
     default:
         return AVERROR(EINVAL);
     }
 
+    return ret;
+}
+
+int av_opt_get(void *obj, const char *name, int search_flags, uint8_t **out_val)
+{
+    void *dst, *target_obj;
+    const AVOption *o = av_opt_find2(obj, name, NULL, 0, search_flags, &target_obj);
+    uint8_t *out, buf[128];
+    int ret;
+
+    if (!o || !target_obj || (o->offset<=0 && o->type != AV_OPT_TYPE_CONST))
+        return AVERROR_OPTION_NOT_FOUND;
+
+    if (o->flags & AV_OPT_FLAG_DEPRECATED)
+        av_log(obj, AV_LOG_WARNING, "The \"%s\" option is deprecated: %s\n", name, o->help);
+
+    dst = (uint8_t *)target_obj + o->offset;
+
+    buf[0] = 0;
+
+    out = buf;
+    ret = opt_get_elem(o, &out, sizeof(buf), dst, search_flags);
+    if (ret < 0)
+        return ret;
+    if (out != buf) {
+        *out_val = out;
+        return 0;
+    }
+
     if (ret >= sizeof(buf))
         return AVERROR(EINVAL);
-    *out_val = av_strdup(buf);
+    *out_val = av_strdup(out);
     return *out_val ? 0 : AVERROR(ENOMEM);
 }