Merge avfiltergraphdesc.c in avfiltergraph.c

Commited in SoC by Vitor Sessak on 2008-03-24 20:46:50

Originally committed as revision 12735 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 338 insertions, 0 deletions

diff --git a/libavfilter/avfiltergraph.c b/libavfilter/avfiltergraph.c
index 33fc0ecf80..c545eda933 100644
--- a/libavfilter/avfiltergraph.c
+++ b/libavfilter/avfiltergraph.c
@@ -1,5 +1,6 @@
 /*
  * filter graphs
+ * copyright (c) 2008 Vitor Sessak
  * copyright (c) 2007 Bobby Bingham
  *
  * This file is part of FFmpeg.
@@ -19,6 +20,9 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include <ctype.h>
+#include <string.h>
+
 #include "avfilter.h"
 #include "avfiltergraph.h"
 
@@ -249,3 +253,337 @@ fail:
     uninit(graph);
     return -1;
 }
+
+
+static void consume_whitespace(const char **buf)
+{
+    *buf += strspn(*buf, " \n\t");
+}
+
+/**
+ * get the next non-whitespace char
+ */
+static char consume_char(const char **buf)
+{
+    char out;
+    consume_whitespace(buf);
+
+    out = **buf;
+
+    if (out)
+        (*buf)++;
+
+    return out;
+}
+
+/**
+ * remove the quotation marks from a string. Ex: "aaa'bb'cc" -> "aaabbcc"
+ */
+static void unquote(char *str)
+{
+    char *p1, *p2;
+    p1=p2=str;
+    while (*p1 != 0) {
+        if (*p1 != '\'')
+            *p2++ = *p1;
+        p1++;
+    }
+
+    *p2 = 0;
+}
+
+/**
+ * Consumes a string from *buf.
+ * @return a copy of the consumed string, which should be free'd after use
+ */
+static char *consume_string(const char **buf)
+{
+    const char *start;
+    char *ret;
+    int size;
+
+    consume_whitespace(buf);
+
+    if (!(**buf))
+        return av_mallocz(1);
+
+    start = *buf;
+
+    *buf += strcspn(*buf, " ()=,'");
+
+    if (**buf == '\'') {
+        char *p = strchr(*buf + 1, '\'');
+        if (p)
+            *buf = p + 1;
+        else
+            *buf += strlen(*buf); // Move the pointer to the null end byte
+    }
+
+    size = *buf - start + 1;
+    ret = av_malloc(size);
+    memcpy(ret, start, size - 1);
+    ret[size-1] = 0;
+
+    unquote(ret);
+
+    return ret;
+}
+
+/**
+ * Parse "(linkname)"
+ * @arg name a pointer (that need to be free'd after use) to the name between
+ *           parenthesis
+ */
+static void parse_link_name(const char **buf, char **name)
+{
+    consume_char(buf);
+
+    *name = consume_string(buf);
+
+    if (!*name[0])
+        goto fail;
+
+    if (consume_char(buf) != ')')
+        goto fail;
+
+    return;
+ fail:
+    av_freep(name);
+    av_log(&log_ctx, AV_LOG_ERROR, "Could not parse link name!\n");
+}
+
+/**
+ * Parse "filter=params"
+ * @arg name a pointer (that need to be free'd after use) to the name of the
+ *           filter
+ * @arg ars  a pointer (that need to be free'd after use) to the args of the
+ *           filter
+ */
+static void parse_filter(const char **buf, char **name, char **opts)
+{
+    *name = consume_string(buf);
+
+    if (**buf == '=') {
+        consume_char(buf);
+        *opts = consume_string(buf);
+    } else {
+        *opts = NULL;
+    }
+
+}
+
+enum LinkType {
+    LinkTypeIn,
+    LinkTypeOut,
+};
+
+/**
+ * A linked-list of the inputs/outputs of the filter chain.
+ */
+typedef struct AVFilterInOut {
+    enum LinkType type;
+    char *name;
+    int instance;
+    int pad_idx;
+
+    struct AVFilterInOut *next;
+} AVFilterInOut;
+
+static void free_inout(AVFilterInOut *head)
+{
+    while (head) {
+        AVFilterInOut *next;
+        next = head->next;
+        av_free(head);
+        head = next;
+    }
+}
+
+/**
+ * Parse "(a1)(link2) ... (etc)"
+ */
+static int parse_inouts(const char **buf, AVFilterInOut **inout, int firstpad,
+                        enum LinkType type, int instance)
+{
+    int pad = firstpad;
+    while (**buf == '(') {
+        AVFilterInOut *inoutn = av_malloc(sizeof(AVFilterInOut));
+        parse_link_name(buf, &inoutn->name);
+        inoutn->type = type;
+        inoutn->instance = instance;
+        inoutn->pad_idx = pad++;
+        inoutn->next = *inout;
+        *inout = inoutn;
+    }
+    return pad;
+}
+
+static AVFilterGraphDesc *parse_chain(const char *filters, int has_in)
+{
+    AVFilterGraphDesc        *ret;
+    AVFilterGraphDescFilter **filterp, *filtern;
+    AVFilterGraphDescLink   **linkp,   *linkn;
+    AVFilterInOut           *inout=NULL;
+    AVFilterInOut           *head;
+
+    int index = 0;
+    char chr = 0;
+    int pad = 0;
+    int has_out = 0;
+
+    consume_whitespace(&filters);
+
+    if(!(ret = av_mallocz(sizeof(AVFilterGraphDesc))))
+        return NULL;
+
+    filterp = &ret->filters;
+    linkp   = &ret->links;
+
+    do {
+        if(chr == ',') {
+            linkn = av_mallocz(sizeof(AVFilterGraphDescLink));
+            linkn->src = index-1;
+            linkn->srcpad = pad;
+            linkn->dst = index;
+            linkn->dstpad = 0;
+
+            *linkp = linkn;
+            linkp = &linkn->next;
+        }
+        pad = parse_inouts(&filters, &inout, chr == ',' || (!has_in),
+                           LinkTypeIn, index);
+
+        filtern = av_mallocz(sizeof(AVFilterGraphDescFilter));
+        filtern->index = index;
+        parse_filter(&filters, &filtern->filter, &filtern->args);
+        *filterp = filtern;
+        filterp = &filtern->next;
+
+        pad = parse_inouts(&filters, &inout, 0,
+                           LinkTypeOut, index);
+        chr = consume_char(&filters);
+        index++;
+    } while (chr == ',' || chr == ';');
+
+    head = inout;
+    for (; inout != NULL; inout = inout->next) {
+        if (inout->instance == -1)
+            continue; // Already processed
+
+        if (!strcmp(inout->name, "in")) {
+            if (!has_in)
+                goto fail;
+            ret->inputs = av_mallocz(sizeof(AVFilterGraphDescExport));
+            ret->inputs->filter = inout->instance;
+            ret->inputs->pad = inout->pad_idx;
+        } else if (!strcmp(inout->name, "out")) {
+            has_out = 1;
+            ret->outputs = av_mallocz(sizeof(AVFilterGraphDescExport));
+            ret->outputs->filter = inout->instance;
+            ret->outputs->pad = inout->pad_idx;
+        } else {
+            AVFilterInOut *p, *src, *dst;
+            for (p = inout->next;
+                 p && strcmp(p->name,inout->name); p = p->next);
+
+            if (!p) {
+                av_log(&log_ctx, AV_LOG_ERROR, "Unmatched link: %s.\n",
+                       inout->name);
+                goto fail;
+            }
+
+            if (p->type == LinkTypeIn && inout->type == LinkTypeOut) {
+                src = inout;
+                dst = p;
+            } else if (p->type == LinkTypeOut && inout->type == LinkTypeIn) {
+                src = p;
+                dst = inout;
+            } else {
+                av_log(&log_ctx, AV_LOG_ERROR, "Two links named '%s' are either both input or both output\n",
+                       inout->name);
+                goto fail;
+            }
+            linkn = av_mallocz(sizeof(AVFilterGraphDescLink));
+
+            linkn->src = src->instance;
+            linkn->srcpad = src->pad_idx;
+            linkn->dst = dst->instance;
+            linkn->dstpad = dst->pad_idx;
+
+            *linkp = linkn;
+            linkp = &linkn->next;
+
+            src->instance = -1;
+            dst->instance = -1;
+        }
+    }
+
+    free_inout(head);
+
+    if (!has_in) {
+        ret->inputs = av_mallocz(sizeof(AVFilterGraphDescExport));
+        ret->inputs->filter = 0;
+    }
+    if (!has_out) {
+        ret->outputs = av_mallocz(sizeof(AVFilterGraphDescExport));
+        ret->outputs->filter = index-1;
+    }
+
+    return ret;
+
+ fail:
+    free_inout(head);
+
+    avfilter_graph_free_desc(ret);
+    return NULL;
+}
+
+/**
+ * Parse a string describing a filter graph.
+ */
+AVFilterGraphDesc *avfilter_graph_parse_chain(const char *filters)
+{
+    AVFilterGraphDesc *ret;
+
+    /* Try first to parse supposing there is no (in) element */
+    if ((ret = parse_chain(filters, 0)))
+        return ret;
+
+    /* Parse supposing there is an (in) element */
+    return parse_chain(filters, 1);
+}
+
+/**
+ * Free a graph description.
+ */
+void avfilter_graph_free_desc(AVFilterGraphDesc *desc)
+{
+    void *next;
+
+    while(desc->filters) {
+        next = desc->filters->next;
+        av_free(desc->filters->filter);
+        av_free(desc->filters->args);
+        av_free(desc->filters);
+        desc->filters = next;
+    }
+
+    while(desc->links) {
+        next = desc->links->next;
+        av_free(desc->links);
+        desc->links = next;
+    }
+
+    while(desc->inputs) {
+        next = desc->inputs->next;
+        av_free(desc->inputs);
+        desc->inputs = next;
+    }
+
+    while(desc->outputs) {
+        next = desc->outputs->next;
+        av_free(desc->outputs);
+        desc->outputs = next;
+    }
+}
+