FFmpeg/libavfilter/f_sendcmd.c
Ganesh Ajjanagadde 92e483f8ed all: use FFDIFFSIGN to resolve possible undefined behavior in comparators
FFDIFFSIGN was created explicitly for this purpose, since the common
return a - b idiom is unsafe regarding overflow on signed integers. It
optimizes to branchless code on common compilers.

FFDIFFSIGN also has the subjective benefit of being easier to read due
to lack of ternary operators.

Tested with FATE.

Things not covered by this are unsigned integers, for which overflows
are well defined, and also places where overflow is clearly impossible,
e.g an instance where the a - b was being done on 24 bit values.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Reviewed-by: Clément Bœsch <u@pkh.me>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
2015-11-03 16:28:30 -05:00

581 lines
17 KiB
C

/*
* Copyright (c) 2012 Stefano Sabatini
*
* 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
*/
/**
* @file
* send commands filter
*/
#include "libavutil/avstring.h"
#include "libavutil/bprint.h"
#include "libavutil/file.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "avfilter.h"
#include "internal.h"
#include "avfiltergraph.h"
#include "audio.h"
#include "video.h"
#define COMMAND_FLAG_ENTER 1
#define COMMAND_FLAG_LEAVE 2
static inline char *make_command_flags_str(AVBPrint *pbuf, int flags)
{
static const char * const flag_strings[] = { "enter", "leave" };
int i, is_first = 1;
av_bprint_init(pbuf, 0, AV_BPRINT_SIZE_AUTOMATIC);
for (i = 0; i < FF_ARRAY_ELEMS(flag_strings); i++) {
if (flags & 1<<i) {
if (!is_first)
av_bprint_chars(pbuf, '+', 1);
av_bprintf(pbuf, "%s", flag_strings[i]);
is_first = 0;
}
}
return pbuf->str;
}
typedef struct {
int flags;
char *target, *command, *arg;
int index;
} Command;
typedef struct {
int64_t start_ts; ///< start timestamp expressed as microseconds units
int64_t end_ts; ///< end timestamp expressed as microseconds units
int index; ///< unique index for these interval commands
Command *commands;
int nb_commands;
int enabled; ///< current time detected inside this interval
} Interval;
typedef struct {
const AVClass *class;
Interval *intervals;
int nb_intervals;
char *commands_filename;
char *commands_str;
} SendCmdContext;
#define OFFSET(x) offsetof(SendCmdContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_VIDEO_PARAM
static const AVOption options[] = {
{ "commands", "set commands", OFFSET(commands_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
{ "c", "set commands", OFFSET(commands_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
{ "filename", "set commands file", OFFSET(commands_filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
{ "f", "set commands file", OFFSET(commands_filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
{ NULL }
};
#define SPACES " \f\t\n\r"
static void skip_comments(const char **buf)
{
while (**buf) {
/* skip leading spaces */
*buf += strspn(*buf, SPACES);
if (**buf != '#')
break;
(*buf)++;
/* skip comment until the end of line */
*buf += strcspn(*buf, "\n");
if (**buf)
(*buf)++;
}
}
#define COMMAND_DELIMS " \f\t\n\r,;"
static int parse_command(Command *cmd, int cmd_count, int interval_count,
const char **buf, void *log_ctx)
{
int ret;
memset(cmd, 0, sizeof(Command));
cmd->index = cmd_count;
/* format: [FLAGS] target command arg */
*buf += strspn(*buf, SPACES);
/* parse flags */
if (**buf == '[') {
(*buf)++; /* skip "[" */
while (**buf) {
int len = strcspn(*buf, "|+]");
if (!strncmp(*buf, "enter", strlen("enter"))) cmd->flags |= COMMAND_FLAG_ENTER;
else if (!strncmp(*buf, "leave", strlen("leave"))) cmd->flags |= COMMAND_FLAG_LEAVE;
else {
char flag_buf[64];
av_strlcpy(flag_buf, *buf, sizeof(flag_buf));
av_log(log_ctx, AV_LOG_ERROR,
"Unknown flag '%s' in interval #%d, command #%d\n",
flag_buf, interval_count, cmd_count);
return AVERROR(EINVAL);
}
*buf += len;
if (**buf == ']')
break;
if (!strspn(*buf, "+|")) {
av_log(log_ctx, AV_LOG_ERROR,
"Invalid flags char '%c' in interval #%d, command #%d\n",
**buf, interval_count, cmd_count);
return AVERROR(EINVAL);
}
if (**buf)
(*buf)++;
}
if (**buf != ']') {
av_log(log_ctx, AV_LOG_ERROR,
"Missing flag terminator or extraneous data found at the end of flags "
"in interval #%d, command #%d\n", interval_count, cmd_count);
return AVERROR(EINVAL);
}
(*buf)++; /* skip "]" */
} else {
cmd->flags = COMMAND_FLAG_ENTER;
}
*buf += strspn(*buf, SPACES);
cmd->target = av_get_token(buf, COMMAND_DELIMS);
if (!cmd->target || !cmd->target[0]) {
av_log(log_ctx, AV_LOG_ERROR,
"No target specified in interval #%d, command #%d\n",
interval_count, cmd_count);
ret = AVERROR(EINVAL);
goto fail;
}
*buf += strspn(*buf, SPACES);
cmd->command = av_get_token(buf, COMMAND_DELIMS);
if (!cmd->command || !cmd->command[0]) {
av_log(log_ctx, AV_LOG_ERROR,
"No command specified in interval #%d, command #%d\n",
interval_count, cmd_count);
ret = AVERROR(EINVAL);
goto fail;
}
*buf += strspn(*buf, SPACES);
cmd->arg = av_get_token(buf, COMMAND_DELIMS);
return 1;
fail:
av_freep(&cmd->target);
av_freep(&cmd->command);
av_freep(&cmd->arg);
return ret;
}
static int parse_commands(Command **cmds, int *nb_cmds, int interval_count,
const char **buf, void *log_ctx)
{
int cmd_count = 0;
int ret, n = 0;
AVBPrint pbuf;
*cmds = NULL;
*nb_cmds = 0;
while (**buf) {
Command cmd;
if ((ret = parse_command(&cmd, cmd_count, interval_count, buf, log_ctx)) < 0)
return ret;
cmd_count++;
/* (re)allocate commands array if required */
if (*nb_cmds == n) {
n = FFMAX(16, 2*n); /* first allocation = 16, or double the number */
*cmds = av_realloc_f(*cmds, n, 2*sizeof(Command));
if (!*cmds) {
av_log(log_ctx, AV_LOG_ERROR,
"Could not (re)allocate command array\n");
return AVERROR(ENOMEM);
}
}
(*cmds)[(*nb_cmds)++] = cmd;
*buf += strspn(*buf, SPACES);
if (**buf && **buf != ';' && **buf != ',') {
av_log(log_ctx, AV_LOG_ERROR,
"Missing separator or extraneous data found at the end of "
"interval #%d, in command #%d\n",
interval_count, cmd_count);
av_log(log_ctx, AV_LOG_ERROR,
"Command was parsed as: flags:[%s] target:%s command:%s arg:%s\n",
make_command_flags_str(&pbuf, cmd.flags), cmd.target, cmd.command, cmd.arg);
return AVERROR(EINVAL);
}
if (**buf == ';')
break;
if (**buf == ',')
(*buf)++;
}
return 0;
}
#define DELIMS " \f\t\n\r,;"
static int parse_interval(Interval *interval, int interval_count,
const char **buf, void *log_ctx)
{
char *intervalstr;
int ret;
*buf += strspn(*buf, SPACES);
if (!**buf)
return 0;
/* reset data */
memset(interval, 0, sizeof(Interval));
interval->index = interval_count;
/* format: INTERVAL COMMANDS */
/* parse interval */
intervalstr = av_get_token(buf, DELIMS);
if (intervalstr && intervalstr[0]) {
char *start, *end;
start = av_strtok(intervalstr, "-", &end);
if ((ret = av_parse_time(&interval->start_ts, start, 1)) < 0) {
av_log(log_ctx, AV_LOG_ERROR,
"Invalid start time specification '%s' in interval #%d\n",
start, interval_count);
goto end;
}
if (end) {
if ((ret = av_parse_time(&interval->end_ts, end, 1)) < 0) {
av_log(log_ctx, AV_LOG_ERROR,
"Invalid end time specification '%s' in interval #%d\n",
end, interval_count);
goto end;
}
} else {
interval->end_ts = INT64_MAX;
}
if (interval->end_ts < interval->start_ts) {
av_log(log_ctx, AV_LOG_ERROR,
"Invalid end time '%s' in interval #%d: "
"cannot be lesser than start time '%s'\n",
end, interval_count, start);
ret = AVERROR(EINVAL);
goto end;
}
} else {
av_log(log_ctx, AV_LOG_ERROR,
"No interval specified for interval #%d\n", interval_count);
ret = AVERROR(EINVAL);
goto end;
}
/* parse commands */
ret = parse_commands(&interval->commands, &interval->nb_commands,
interval_count, buf, log_ctx);
end:
av_free(intervalstr);
return ret;
}
static int parse_intervals(Interval **intervals, int *nb_intervals,
const char *buf, void *log_ctx)
{
int interval_count = 0;
int ret, n = 0;
*intervals = NULL;
*nb_intervals = 0;
if (!buf)
return 0;
while (1) {
Interval interval;
skip_comments(&buf);
if (!(*buf))
break;
if ((ret = parse_interval(&interval, interval_count, &buf, log_ctx)) < 0)
return ret;
buf += strspn(buf, SPACES);
if (*buf) {
if (*buf != ';') {
av_log(log_ctx, AV_LOG_ERROR,
"Missing terminator or extraneous data found at the end of interval #%d\n",
interval_count);
return AVERROR(EINVAL);
}
buf++; /* skip ';' */
}
interval_count++;
/* (re)allocate commands array if required */
if (*nb_intervals == n) {
n = FFMAX(16, 2*n); /* first allocation = 16, or double the number */
*intervals = av_realloc_f(*intervals, n, 2*sizeof(Interval));
if (!*intervals) {
av_log(log_ctx, AV_LOG_ERROR,
"Could not (re)allocate intervals array\n");
return AVERROR(ENOMEM);
}
}
(*intervals)[(*nb_intervals)++] = interval;
}
return 0;
}
static int cmp_intervals(const void *a, const void *b)
{
const Interval *i1 = a;
const Interval *i2 = b;
return 2 * FFDIFFSIGN(i1->start_ts, i2->start_ts) + FFDIFFSIGN(i1->index, i2->index);
}
static av_cold int init(AVFilterContext *ctx)
{
SendCmdContext *s = ctx->priv;
int ret, i, j;
if ((!!s->commands_filename + !!s->commands_str) != 1) {
av_log(ctx, AV_LOG_ERROR,
"One and only one of the filename or commands options must be specified\n");
return AVERROR(EINVAL);
}
if (s->commands_filename) {
uint8_t *file_buf, *buf;
size_t file_bufsize;
ret = av_file_map(s->commands_filename,
&file_buf, &file_bufsize, 0, ctx);
if (ret < 0)
return ret;
/* create a 0-terminated string based on the read file */
buf = av_malloc(file_bufsize + 1);
if (!buf) {
av_file_unmap(file_buf, file_bufsize);
return AVERROR(ENOMEM);
}
memcpy(buf, file_buf, file_bufsize);
buf[file_bufsize] = 0;
av_file_unmap(file_buf, file_bufsize);
s->commands_str = buf;
}
if ((ret = parse_intervals(&s->intervals, &s->nb_intervals,
s->commands_str, ctx)) < 0)
return ret;
if (s->nb_intervals == 0) {
av_log(ctx, AV_LOG_ERROR, "No commands were specified\n");
return AVERROR(EINVAL);
}
qsort(s->intervals, s->nb_intervals, sizeof(Interval), cmp_intervals);
av_log(ctx, AV_LOG_DEBUG, "Parsed commands:\n");
for (i = 0; i < s->nb_intervals; i++) {
AVBPrint pbuf;
Interval *interval = &s->intervals[i];
av_log(ctx, AV_LOG_VERBOSE, "start_time:%f end_time:%f index:%d\n",
(double)interval->start_ts/1000000, (double)interval->end_ts/1000000, interval->index);
for (j = 0; j < interval->nb_commands; j++) {
Command *cmd = &interval->commands[j];
av_log(ctx, AV_LOG_VERBOSE,
" [%s] target:%s command:%s arg:%s index:%d\n",
make_command_flags_str(&pbuf, cmd->flags), cmd->target, cmd->command, cmd->arg, cmd->index);
}
}
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
SendCmdContext *s = ctx->priv;
int i, j;
for (i = 0; i < s->nb_intervals; i++) {
Interval *interval = &s->intervals[i];
for (j = 0; j < interval->nb_commands; j++) {
Command *cmd = &interval->commands[j];
av_freep(&cmd->target);
av_freep(&cmd->command);
av_freep(&cmd->arg);
}
av_freep(&interval->commands);
}
av_freep(&s->intervals);
}
static int filter_frame(AVFilterLink *inlink, AVFrame *ref)
{
AVFilterContext *ctx = inlink->dst;
SendCmdContext *s = ctx->priv;
int64_t ts;
int i, j, ret;
if (ref->pts == AV_NOPTS_VALUE)
goto end;
ts = av_rescale_q(ref->pts, inlink->time_base, AV_TIME_BASE_Q);
#define WITHIN_INTERVAL(ts, start_ts, end_ts) ((ts) >= (start_ts) && (ts) < (end_ts))
for (i = 0; i < s->nb_intervals; i++) {
Interval *interval = &s->intervals[i];
int flags = 0;
if (!interval->enabled && WITHIN_INTERVAL(ts, interval->start_ts, interval->end_ts)) {
flags += COMMAND_FLAG_ENTER;
interval->enabled = 1;
}
if (interval->enabled && !WITHIN_INTERVAL(ts, interval->start_ts, interval->end_ts)) {
flags += COMMAND_FLAG_LEAVE;
interval->enabled = 0;
}
if (flags) {
AVBPrint pbuf;
av_log(ctx, AV_LOG_VERBOSE,
"[%s] interval #%d start_ts:%f end_ts:%f ts:%f\n",
make_command_flags_str(&pbuf, flags), interval->index,
(double)interval->start_ts/1000000, (double)interval->end_ts/1000000,
(double)ts/1000000);
for (j = 0; flags && j < interval->nb_commands; j++) {
Command *cmd = &interval->commands[j];
char buf[1024];
if (cmd->flags & flags) {
av_log(ctx, AV_LOG_VERBOSE,
"Processing command #%d target:%s command:%s arg:%s\n",
cmd->index, cmd->target, cmd->command, cmd->arg);
ret = avfilter_graph_send_command(inlink->graph,
cmd->target, cmd->command, cmd->arg,
buf, sizeof(buf),
AVFILTER_CMD_FLAG_ONE);
av_log(ctx, AV_LOG_VERBOSE,
"Command reply for command #%d: ret:%s res:%s\n",
cmd->index, av_err2str(ret), buf);
}
}
}
}
end:
switch (inlink->type) {
case AVMEDIA_TYPE_VIDEO:
case AVMEDIA_TYPE_AUDIO:
return ff_filter_frame(inlink->dst->outputs[0], ref);
}
return AVERROR(ENOSYS);
}
#if CONFIG_SENDCMD_FILTER
#define sendcmd_options options
AVFILTER_DEFINE_CLASS(sendcmd);
static const AVFilterPad sendcmd_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
},
{ NULL }
};
static const AVFilterPad sendcmd_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
},
{ NULL }
};
AVFilter ff_vf_sendcmd = {
.name = "sendcmd",
.description = NULL_IF_CONFIG_SMALL("Send commands to filters."),
.init = init,
.uninit = uninit,
.priv_size = sizeof(SendCmdContext),
.inputs = sendcmd_inputs,
.outputs = sendcmd_outputs,
.priv_class = &sendcmd_class,
};
#endif
#if CONFIG_ASENDCMD_FILTER
#define asendcmd_options options
AVFILTER_DEFINE_CLASS(asendcmd);
static const AVFilterPad asendcmd_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.filter_frame = filter_frame,
},
{ NULL }
};
static const AVFilterPad asendcmd_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
},
{ NULL }
};
AVFilter ff_af_asendcmd = {
.name = "asendcmd",
.description = NULL_IF_CONFIG_SMALL("Send commands to filters."),
.init = init,
.uninit = uninit,
.priv_size = sizeof(SendCmdContext),
.inputs = asendcmd_inputs,
.outputs = asendcmd_outputs,
.priv_class = &asendcmd_class,
};
#endif