ffmpeg/libavfilter/avfiltergraph.c

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/*
* filter graphs
* copyright (c) 2008 Vitor Sessak
* copyright (c) 2007 Bobby Bingham
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <ctype.h>
#include <string.h>
#include "avfilter.h"
#include "avfiltergraph.h"
/**
* For use in av_log
*/
static const char *log_name(void *p)
{
return "Filter parser";
}
static const AVClass filter_parser_class = {
"Filter parser",
log_name
};
static const AVClass *log_ctx = &filter_parser_class;
static void uninit(AVFilterGraph *graph)
{
for(; graph->filter_count > 0; graph->filter_count --)
avfilter_destroy(graph->filters[graph->filter_count - 1]);
av_freep(&graph->filters);
}
/* TODO: insert in sorted order */
void avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
{
graph->filters = av_realloc(graph->filters,
sizeof(AVFilterContext*) * ++graph->filter_count);
graph->filters[graph->filter_count - 1] = filter;
}
/* search intelligently, once we insert in order */
AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
{
int i;
if(!name)
return NULL;
for(i = 0; i < graph->filter_count; i ++)
if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
return graph->filters[i];
return NULL;
}
static int query_formats(AVFilterGraph *graph)
{
int i, j;
/* ask all the sub-filters for their supported colorspaces */
for(i = 0; i < graph->filter_count; i ++) {
if(graph->filters[i]->filter->query_formats)
graph->filters[i]->filter->query_formats(graph->filters[i]);
else
avfilter_default_query_formats(graph->filters[i]);
}
/* go through and merge as many format lists as possible */
for(i = 0; i < graph->filter_count; i ++) {
AVFilterContext *filter = graph->filters[i];
for(j = 0; j < filter->input_count; j ++) {
AVFilterLink *link;
if(!(link = filter->inputs[j]))
continue;
if(link->in_formats != link->out_formats) {
if(!avfilter_merge_formats(link->in_formats,
link->out_formats)) {
/* couldn't merge format lists. auto-insert scale filter */
AVFilterContext *scale;
if(!(scale =
avfilter_open(avfilter_get_by_name("scale"), NULL)))
return -1;
if(scale->filter->init(scale, NULL, NULL) ||
avfilter_insert_filter(link, scale, 0, 0)) {
avfilter_destroy(scale);
return -1;
}
avfilter_graph_add_filter(graph, scale);
scale->filter->query_formats(scale);
if(!avfilter_merge_formats(scale-> inputs[0]->in_formats,
scale-> inputs[0]->out_formats) ||
!avfilter_merge_formats(scale->outputs[0]->in_formats,
scale->outputs[0]->out_formats))
return -1;
}
}
}
}
return 0;
}
static void pick_format(AVFilterLink *link)
{
if(!link || !link->in_formats)
return;
link->in_formats->format_count = 1;
link->format = link->in_formats->formats[0];
avfilter_formats_unref(&link->in_formats);
avfilter_formats_unref(&link->out_formats);
}
static void pick_formats(AVFilterGraph *graph)
{
int i, j;
for(i = 0; i < graph->filter_count; i ++) {
AVFilterContext *filter = graph->filters[i];
for(j = 0; j < filter->input_count; j ++)
pick_format(filter->inputs[j]);
for(j = 0; j < filter->output_count; j ++)
pick_format(filter->outputs[j]);
}
}
int avfilter_graph_config_formats(AVFilterGraph *graph)
{
/* find supported formats from sub-filters, and merge along links */
if(query_formats(graph))
return -1;
/* Once everything is merged, it's possible that we'll still have
* multiple valid colorspace choices. We pick the first one. */
pick_formats(graph);
return 0;
}
static int create_filter(AVFilterGraph *ctx, int index, char *name,
char *args)
{
AVFilterContext *filt;
AVFilter *filterdef;
char tmp[20];
snprintf(tmp, 20, "%d", index);
if(!(filterdef = avfilter_get_by_name(name)) ||
!(filt = avfilter_open(filterdef, tmp))) {
av_log(&log_ctx, AV_LOG_ERROR,
"error creating filter '%s'\n", name);
return -1;
}
avfilter_graph_add_filter(ctx, filt);
if(avfilter_init_filter(filt, args, NULL)) {
av_log(&log_ctx, AV_LOG_ERROR,
"error initializing filter '%s'\n", name);
return -1;
}
return 0;
}
static int link_filter(AVFilterGraph *ctx, int src, int srcpad,
int dst, int dstpad)
{
AVFilterContext *filt, *filtb;
char tmp[20];
snprintf(tmp, 20, "%d", src);
if(!(filt = avfilter_graph_get_filter(ctx, tmp))) {
av_log(&log_ctx, AV_LOG_ERROR, "link source does not exist in graph\n");
return -1;
}
snprintf(tmp, 20, "%d", dst);
if(!(filtb = avfilter_graph_get_filter(ctx, tmp))) {
av_log(&log_ctx, AV_LOG_ERROR, "link destination does not exist in graph\n");
return -1;
}
if(avfilter_link(filt, srcpad, filtb, dstpad)) {
av_log(&log_ctx, AV_LOG_ERROR, "cannot create link between source and destination filters\n");
return -1;
}
return 0;
}
int graph_load_from_desc3(AVFilterGraph *graph, AVFilterGraphDesc *desc, AVFilterContext *in, int inpad, AVFilterContext *out, int outpad)
{
AVFilterGraphDescExport *curpad;
char tmp[20];
AVFilterContext *filt;
AVFilterGraphDescFilter *curfilt;
AVFilterGraphDescLink *curlink;
/* create all filters */
for(curfilt = desc->filters; curfilt; curfilt = curfilt->next) {
if (create_filter(graph, curfilt->index, curfilt->filter,
curfilt->args) < 0)
goto fail;
}
/* create all links */
for(curlink = desc->links; curlink; curlink = curlink->next) {
if (link_filter(graph, curlink->src, curlink->srcpad,
curlink->dst, curlink->dstpad) < 0)
goto fail;
}
/* export all input pads */
for(curpad = desc->inputs; curpad; curpad = curpad->next) {
snprintf(tmp, 20, "%d", curpad->filter);
if(!(filt = avfilter_graph_get_filter(graph, tmp))) {
av_log(&log_ctx, AV_LOG_ERROR, "filter owning exported pad does not exist\n");
goto fail;
}
if(avfilter_link(in, inpad, filt, curpad->pad)) {
av_log(&log_ctx, AV_LOG_ERROR, "cannot create link between source and destination filters\n");
goto fail;
}
}
/* export all output pads */
for(curpad = desc->outputs; curpad; curpad = curpad->next) {
snprintf(tmp, 20, "%d", curpad->filter);
if(!(filt = avfilter_graph_get_filter(graph, tmp))) {
av_log(&log_ctx, AV_LOG_ERROR, "filter owning exported pad does not exist\n");
goto fail;
}
if(avfilter_link(filt, curpad->pad, out, outpad)) {
av_log(&log_ctx, AV_LOG_ERROR, "cannot create link between source and destination filters\n");
goto fail;
}
}
return 0;
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;
}
}