diff --git a/Changelog b/Changelog
index 110e437f23..8a60d568df 100644
--- a/Changelog
+++ b/Changelog
@@ -10,6 +10,7 @@ version <next>:
 - perms and aperms filters
 - audio filtering support in ffplay
 - 10% faster aac encoding on x86 and MIPS
+- sine audio filter source
 
 
 version 1.2:
diff --git a/doc/APIchanges b/doc/APIchanges
index 41552aa38f..255f9147ff 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -15,6 +15,9 @@ libavutil:     2012-10-22
 
 API changes, most recent first:
 
+2013-03-20 - xxxxxxx - lavu 52.22.100 - opt.h
+  Add AV_OPT_TYPE_DURATION value to AVOptionType enum.
+
 2013-03-17 - xxxxxx - lavu 52.20.100 - opt.h
   Add AV_OPT_TYPE_VIDEO_RATE value to AVOptionType enum.
 
diff --git a/doc/demuxers.texi b/doc/demuxers.texi
index 0861287e76..fc5087188f 100644
--- a/doc/demuxers.texi
+++ b/doc/demuxers.texi
@@ -78,6 +78,9 @@ Duration of the file. This information can be specified from the file;
 specifying it here may be more efficient or help if the information from the
 file is not available or accurate.
 
+If the duration is set for all files, then it is possible to seek in the
+whole concatenated video.
+
 @end table
 
 @subsection Options
diff --git a/doc/filters.texi b/doc/filters.texi
index eb5962bd0d..74a682af86 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -1653,6 +1653,57 @@ ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
 For more information about libflite, check:
 @url{http://www.speech.cs.cmu.edu/flite/}
 
+@section sine
+
+Generate an audio signal made of a sine wave with amplitude 1/8.
+
+The audio signal is bit-exact.
+
+It accepts a list of options in the form of @var{key}=@var{value} pairs
+separated by ":". If the option name is omitted, the first option is the
+frequency and the second option is the beep factor.
+
+The supported options are:
+
+@table @option
+
+@item frequency, f
+Set the carrier frequency. Default is 440 Hz.
+
+@item beep_factor, b
+Enable a periodic beep every second with frequency @var{beep_factor} times
+the carrier frequency. Default is 0, meaning the beep is disabled.
+
+@item sample_rate, s
+Specify the sample rate, default is 44100.
+
+@item duration, d
+Specify the duration of the generated audio stream.
+
+@item samples_per_frame
+Set the number of samples per output frame, default is 1024.
+@end table
+
+@subsection Examples
+
+@itemize
+
+@item
+Generate a simple 440 Hz sine wave:
+@example
+sine
+@end example
+
+@item
+Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
+@example
+sine=220:4:d=5
+sine=f=220:b=4:d=5
+sine=frequency=220:beep_factor=4:duration=5
+@end example
+
+@end itemize
+
 @c man end AUDIO SOURCES
 
 @chapter Audio Sinks
diff --git a/ffmpeg.c b/ffmpeg.c
index 67e2de18f2..12c7a2891f 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -482,7 +482,7 @@ static void exit_program(void)
         av_frame_free(&input_streams[i]->filter_frame);
         av_dict_free(&input_streams[i]->opts);
         avsubtitle_free(&input_streams[i]->prev_sub.subtitle);
-        avcodec_free_frame(&input_streams[i]->sub2video.frame);
+        av_frame_free(&input_streams[i]->sub2video.frame);
         av_freep(&input_streams[i]->filters);
         av_freep(&input_streams[i]);
     }
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 0040a333ad..690b1cbcd3 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -90,6 +90,7 @@ OBJS-$(CONFIG_VOLUMEDETECT_FILTER)           += af_volumedetect.o
 OBJS-$(CONFIG_AEVALSRC_FILTER)               += asrc_aevalsrc.o
 OBJS-$(CONFIG_ANULLSRC_FILTER)               += asrc_anullsrc.o
 OBJS-$(CONFIG_FLITE_FILTER)                  += asrc_flite.o
+OBJS-$(CONFIG_SINE_FILTER)                   += asrc_sine.o
 
 OBJS-$(CONFIG_ANULLSINK_FILTER)              += asink_anullsink.o
 
diff --git a/libavfilter/af_volume.c b/libavfilter/af_volume.c
index 226ef93969..447e8d57fe 100644
--- a/libavfilter/af_volume.c
+++ b/libavfilter/af_volume.c
@@ -59,14 +59,6 @@ AVFILTER_DEFINE_CLASS(volume);
 static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     VolumeContext *vol = ctx->priv;
-    static const char *shorthand[] = { "volume", "precision", NULL };
-    int ret;
-
-    vol->class = &volume_class;
-    av_opt_set_defaults(vol);
-
-    if ((ret = av_opt_set_from_string(vol, args, shorthand, "=", ":")) < 0)
-        return ret;
 
     if (vol->precision == PRECISION_FIXED) {
         vol->volume_i = (int)(vol->volume * 256 + 0.5);
@@ -79,8 +71,7 @@ static av_cold int init(AVFilterContext *ctx, const char *args)
                precision_str[vol->precision]);
     }
 
-    av_opt_free(vol);
-    return ret;
+    return 0;
 }
 
 static int query_formats(AVFilterContext *ctx)
@@ -299,6 +290,8 @@ static const AVFilterPad avfilter_af_volume_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] = { "volume", "precision", NULL };
+
 AVFilter avfilter_af_volume = {
     .name           = "volume",
     .description    = NULL_IF_CONFIG_SMALL("Change input volume."),
@@ -308,4 +301,5 @@ AVFilter avfilter_af_volume = {
     .inputs         = avfilter_af_volume_inputs,
     .outputs        = avfilter_af_volume_outputs,
     .priv_class     = &volume_class,
+    .shorthand      = shorthand,
 };
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 086e6c90ce..45a67e50da 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -86,6 +86,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(AEVALSRC,       aevalsrc,       asrc);
     REGISTER_FILTER(ANULLSRC,       anullsrc,       asrc);
     REGISTER_FILTER(FLITE,          flite,          asrc);
+    REGISTER_FILTER(SINE,           sine,           asrc);
 
     REGISTER_FILTER(ANULLSINK,      anullsink,      asink);
 
diff --git a/libavfilter/asrc_sine.c b/libavfilter/asrc_sine.c
new file mode 100644
index 0000000000..8b406ff455
--- /dev/null
+++ b/libavfilter/asrc_sine.c
@@ -0,0 +1,228 @@
+/*
+ * Copyright (c) 2013 Nicolas George
+ *
+ * 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 "libavutil/avassert.h"
+#include "libavutil/channel_layout.h"
+#include "libavutil/opt.h"
+#include "audio.h"
+#include "avfilter.h"
+#include "internal.h"
+
+typedef struct {
+    const AVClass *class;
+    double frequency;
+    double beep_factor;
+    int samples_per_frame;
+    int sample_rate;
+    int64_t duration;
+    int16_t *sin;
+    int64_t pts;
+    uint32_t phi;  ///< current phase of the sine (2pi = 1<<32)
+    uint32_t dphi; ///< phase increment between two samples
+    unsigned beep_period;
+    unsigned beep_index;
+    unsigned beep_length;
+    uint32_t phi_beep;  ///< current phase of the beep
+    uint32_t dphi_beep; ///< phase increment of the beep
+} SineContext;
+
+#define CONTEXT SineContext
+#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+
+#define OPT_GENERIC(name, field, def, min, max, descr, type, deffield, ...) \
+    { name, descr, offsetof(CONTEXT, field), AV_OPT_TYPE_ ## type,          \
+      { .deffield = def }, min, max, FLAGS, __VA_ARGS__ }
+
+#define OPT_INT(name, field, def, min, max, descr, ...) \
+    OPT_GENERIC(name, field, def, min, max, descr, INT, i64, __VA_ARGS__)
+
+#define OPT_DBL(name, field, def, min, max, descr, ...) \
+    OPT_GENERIC(name, field, def, min, max, descr, DOUBLE, dbl, __VA_ARGS__)
+
+#define OPT_DUR(name, field, def, min, max, descr, ...) \
+    OPT_GENERIC(name, field, def, min, max, descr, DURATION, str, __VA_ARGS__)
+
+static const AVOption sine_options[] = {
+    OPT_DBL("frequency",         frequency,            440, 0, INFINITY,  "set the sine frequency"),
+    OPT_DBL("f",                 frequency,            440, 0, INFINITY,  "set the sine frequency"),
+    OPT_DBL("beep_factor",       beep_factor,            0, 0, INFINITY,  "set the beep fequency factor"),
+    OPT_DBL("b",                 beep_factor,            0, 0, INFINITY,  "set the beep fequency factor"),
+    OPT_INT("sample_rate",       sample_rate,        44100, 1, INT_MAX,   "set the sample rate"),
+    OPT_INT("r",                 sample_rate,        44100, 1, INT_MAX,   "set the sample rate"),
+    OPT_DUR("duration",          duration,               0, 0, INT64_MAX, "set the audio duration"),
+    OPT_DUR("d",                 duration,               0, 0, INT64_MAX, "set the audio duration"),
+    OPT_INT("samples_per_frame", samples_per_frame,   1024, 0, INT_MAX,   "set the number of samples per frame"),
+    {NULL},
+};
+
+AVFILTER_DEFINE_CLASS(sine);
+
+#define LOG_PERIOD 15
+#define AMPLITUDE 4095
+#define AMPLITUDE_SHIFT 3
+
+static void make_sin_table(int16_t *sin)
+{
+    unsigned half_pi = 1 << (LOG_PERIOD - 2);
+    unsigned ampls = AMPLITUDE << AMPLITUDE_SHIFT;
+    uint64_t unit2 = (uint64_t)(ampls * ampls) << 32;
+    unsigned step, i, c, s, k, new_k, n2;
+
+    /* Principle: if u = exp(i*a1) and v = exp(i*a2), then
+       exp(i*(a1+a2)/2) = (u+v) / length(u+v) */
+    sin[0] = 0;
+    sin[half_pi] = ampls;
+    for (step = half_pi; step > 1; step /= 2) {
+        /* k = (1 << 16) * amplitude / length(u+v)
+           In exact values, k is constant at a given step */
+        k = 0x10000;
+        for (i = 0; i < half_pi / 2; i += step) {
+            s = sin[i] + sin[i + step];
+            c = sin[half_pi - i] + sin[half_pi - i - step];
+            n2 = s * s + c * c;
+            /* Newton's method to solve n² * k² = unit² */
+            while (1) {
+                new_k = (k + unit2 / ((uint64_t)k * n2) + 1) >> 1;
+                if (k == new_k)
+                    break;
+                k = new_k;
+            }
+            sin[i + step / 2] = (k * s + 0x7FFF) >> 16;
+            sin[half_pi - i - step / 2] = (k * c + 0x8000) >> 16;
+        }
+    }
+    /* Unshift amplitude */
+    for (i = 0; i <= half_pi; i++)
+        sin[i] = (sin[i] + (1 << (AMPLITUDE_SHIFT - 1))) >> AMPLITUDE_SHIFT;
+    /* Use symmetries to fill the other three quarters */
+    for (i = 0; i < half_pi; i++)
+        sin[half_pi * 2 - i] = sin[i];
+    for (i = 0; i < 2 * half_pi; i++)
+        sin[i + 2 * half_pi] = -sin[i];
+}
+
+static av_cold int init(AVFilterContext *ctx, const char *args)
+{
+    SineContext *sine = ctx->priv;
+    static const char *shorthand[] = { "frequency", "beep_factor", NULL };
+    int ret;
+
+    sine->class = &sine_class;
+    av_opt_set_defaults(sine);
+
+    if ((ret = av_opt_set_from_string(sine, args, shorthand, "=", ":")) < 0)
+        return ret;
+    if (!(sine->sin = av_malloc(sizeof(*sine->sin) << LOG_PERIOD)))
+        return AVERROR(ENOMEM);
+    sine->dphi = ldexp(sine->frequency, 32) / sine->sample_rate + 0.5;
+    make_sin_table(sine->sin);
+
+    if (sine->beep_factor) {
+        sine->beep_period = sine->sample_rate;
+        sine->beep_length = sine->beep_period / 25;
+        sine->dphi_beep = ldexp(sine->beep_factor * sine->frequency, 32) /
+                          sine->sample_rate + 0.5;
+    }
+
+    return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    SineContext *sine = ctx->priv;
+
+    av_freep(&sine->sin);
+}
+
+static av_cold int query_formats(AVFilterContext *ctx)
+{
+    SineContext *sine = ctx->priv;
+    static const int64_t chlayouts[] = { AV_CH_LAYOUT_MONO, -1 };
+    int sample_rates[] = { sine->sample_rate, -1 };
+    static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16,
+                                                       AV_SAMPLE_FMT_NONE };
+
+    ff_set_common_formats (ctx, ff_make_format_list(sample_fmts));
+    ff_set_common_channel_layouts(ctx, avfilter_make_format64_list(chlayouts));
+    ff_set_common_samplerates(ctx, ff_make_format_list(sample_rates));
+    return 0;
+}
+
+static av_cold int config_props(AVFilterLink *outlink)
+{
+    SineContext *sine = outlink->src->priv;
+    sine->duration = av_rescale(sine->duration, sine->sample_rate, AV_TIME_BASE);
+    return 0;
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+    SineContext *sine = outlink->src->priv;
+    AVFrame *frame;
+    int i, nb_samples = sine->samples_per_frame;
+    int16_t *samples;
+
+    if (sine->duration) {
+        nb_samples = FFMIN(nb_samples, sine->duration - sine->pts);
+        av_assert1(nb_samples >= 0);
+        if (!nb_samples)
+            return AVERROR_EOF;
+    }
+    if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
+        return AVERROR(ENOMEM);
+    samples = (int16_t *)frame->data[0];
+
+    for (i = 0; i < nb_samples; i++) {
+        samples[i] = sine->sin[sine->phi >> (32 - LOG_PERIOD)];
+        sine->phi += sine->dphi;
+        if (sine->beep_index < sine->beep_length) {
+            samples[i] += sine->sin[sine->phi_beep >> (32 - LOG_PERIOD)] << 1;
+            sine->phi_beep += sine->dphi_beep;
+        }
+        if (++sine->beep_index == sine->beep_period)
+            sine->beep_index = 0;
+    }
+
+    frame->pts = sine->pts;
+    sine->pts += nb_samples;
+    return ff_filter_frame(outlink, frame);
+}
+
+static const AVFilterPad sine_outputs[] = {
+    {
+        .name          = "default",
+        .type          = AVMEDIA_TYPE_AUDIO,
+        .request_frame = request_frame,
+        .config_props  = config_props,
+    },
+    { NULL }
+};
+
+AVFilter avfilter_asrc_sine = {
+    .name          = "sine",
+    .description   = NULL_IF_CONFIG_SMALL("Generate sine wave audio signal."),
+    .query_formats = query_formats,
+    .init          = init,
+    .uninit        = uninit,
+    .priv_size     = sizeof(SineContext),
+    .inputs        = NULL,
+    .outputs       = sine_outputs,
+    .priv_class    = &sine_class,
+};
diff --git a/libavfilter/avf_concat.c b/libavfilter/avf_concat.c
index 7b5d5913d3..2b3640b1b0 100644
--- a/libavfilter/avf_concat.c
+++ b/libavfilter/avf_concat.c
@@ -232,7 +232,7 @@ static void close_input(AVFilterContext *ctx, unsigned in_no)
            ctx->input_pads[in_no].name, cat->nb_in_active);
 }
 
-static void find_next_delta_ts(AVFilterContext *ctx)
+static void find_next_delta_ts(AVFilterContext *ctx, int64_t *seg_delta)
 {
     ConcatContext *cat = ctx->priv;
     unsigned i = cat->cur_idx;
@@ -243,13 +243,15 @@ static void find_next_delta_ts(AVFilterContext *ctx)
     for (; i < imax; i++)
         pts = FFMAX(pts, cat->in[i].pts);
     cat->delta_ts += pts;
+    *seg_delta = pts;
 }
 
-static int send_silence(AVFilterContext *ctx, unsigned in_no, unsigned out_no)
+static int send_silence(AVFilterContext *ctx, unsigned in_no, unsigned out_no,
+                        int64_t seg_delta)
 {
     ConcatContext *cat = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[out_no];
-    int64_t base_pts = cat->in[in_no].pts + cat->delta_ts;
+    int64_t base_pts = cat->in[in_no].pts + cat->delta_ts - seg_delta;
     int64_t nb_samples, sent = 0;
     int frame_nb_samples, ret;
     AVRational rate_tb = { 1, ctx->inputs[in_no]->sample_rate };
@@ -258,7 +260,7 @@ static int send_silence(AVFilterContext *ctx, unsigned in_no, unsigned out_no)
 
     if (!rate_tb.den)
         return AVERROR_BUG;
-    nb_samples = av_rescale_q(cat->delta_ts - base_pts,
+    nb_samples = av_rescale_q(seg_delta - cat->in[in_no].pts,
                               outlink->time_base, rate_tb);
     frame_nb_samples = FFMAX(9600, rate_tb.den / 5); /* arbitrary */
     while (nb_samples) {
@@ -283,8 +285,9 @@ static int flush_segment(AVFilterContext *ctx)
     int ret;
     ConcatContext *cat = ctx->priv;
     unsigned str, str_max;
+    int64_t seg_delta;
 
-    find_next_delta_ts(ctx);
+    find_next_delta_ts(ctx, &seg_delta);
     cat->cur_idx += ctx->nb_outputs;
     cat->nb_in_active = ctx->nb_outputs;
     av_log(ctx, AV_LOG_VERBOSE, "Segment finished at pts=%"PRId64"\n",
@@ -295,7 +298,8 @@ static int flush_segment(AVFilterContext *ctx)
         str = cat->nb_streams[AVMEDIA_TYPE_VIDEO];
         str_max = str + cat->nb_streams[AVMEDIA_TYPE_AUDIO];
         for (; str < str_max; str++) {
-            ret = send_silence(ctx, cat->cur_idx - ctx->nb_outputs + str, str);
+            ret = send_silence(ctx, cat->cur_idx - ctx->nb_outputs + str, str,
+                               seg_delta);
             if (ret < 0)
                 return ret;
         }
@@ -354,17 +358,8 @@ static int request_frame(AVFilterLink *outlink)
 static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     ConcatContext *cat = ctx->priv;
-    int ret;
     unsigned seg, type, str;
 
-    cat->class = &concat_class;
-    av_opt_set_defaults(cat);
-    ret = av_set_options_string(cat, args, "=", ":");
-    if (ret < 0) {
-        av_log(ctx, AV_LOG_ERROR, "Error parsing options: '%s'\n", args);
-        return ret;
-    }
-
     /* create input pads */
     for (seg = 0; seg < cat->nb_segments; seg++) {
         for (type = 0; type < TYPE_ALL; type++) {
@@ -414,6 +409,8 @@ static av_cold void uninit(AVFilterContext *ctx)
     av_free(cat->in);
 }
 
+static const char *const shorthand[] = { NULL };
+
 AVFilter avfilter_avf_concat = {
     .name          = "concat",
     .description   = NULL_IF_CONFIG_SMALL("Concatenate audio and video streams."),
@@ -424,4 +421,5 @@ AVFilter avfilter_avf_concat = {
     .inputs        = NULL,
     .outputs       = NULL,
     .priv_class    = &concat_class,
+    .shorthand     = shorthand,
 };
diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
index 1d278178fe..8a907dc085 100644
--- a/libavfilter/avfilter.c
+++ b/libavfilter/avfilter.c
@@ -24,6 +24,7 @@
 #include "libavutil/channel_layout.h"
 #include "libavutil/common.h"
 #include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "libavutil/rational.h"
 #include "libavutil/samplefmt.h"
@@ -556,6 +557,8 @@ void avfilter_free(AVFilterContext *filter)
 
     if (filter->filter->uninit)
         filter->filter->uninit(filter);
+    if (filter->filter->shorthand)
+        av_opt_free(filter->priv);
 
     for (i = 0; i < filter->nb_inputs; i++) {
         if ((link = filter->inputs[i])) {
@@ -600,6 +603,17 @@ int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque
 {
     int ret=0;
 
+    if (filter->filter->shorthand) {
+        av_assert0(filter->priv);
+        av_assert0(filter->filter->priv_class);
+        *(const AVClass **)filter->priv = filter->filter->priv_class;
+        av_opt_set_defaults(filter->priv);
+        ret = av_opt_set_from_string(filter->priv, args,
+                                     filter->filter->shorthand, "=", ":");
+        if (ret < 0)
+            return ret;
+        args = NULL;
+    }
     if (filter->filter->init_opaque)
         ret = filter->filter->init_opaque(filter, args, opaque);
     else if (filter->filter->init)
diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
index 45ad6f9f58..455161fa34 100644
--- a/libavfilter/avfilter.h
+++ b/libavfilter/avfilter.h
@@ -486,6 +486,15 @@ typedef struct AVFilter {
     int (*init_opaque)(AVFilterContext *ctx, const char *args, void *opaque);
 
     const AVClass *priv_class;      ///< private class, containing filter specific options
+
+    /**
+     * Shorthand syntax for init arguments.
+     * If this field is set (even to an empty list), just before init the
+     * private class will be set and the arguments string will be parsed
+     * using av_opt_set_from_string() with "=" and ":" delimiters, and
+     * av_opt_free() will be called just after uninit.
+     */
+    const char *const *shorthand;
 } AVFilter;
 
 /** An instance of a filter */
diff --git a/libavfilter/version.h b/libavfilter/version.h
index 88a782cad8..f592fc16b8 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -29,8 +29,8 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  47
-#define LIBAVFILTER_VERSION_MICRO 104
+#define LIBAVFILTER_VERSION_MINOR  48
+#define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \
diff --git a/libavfilter/vf_crop.c b/libavfilter/vf_crop.c
index 17487a29cc..f99d1a7ce9 100644
--- a/libavfilter/vf_crop.c
+++ b/libavfilter/vf_crop.c
@@ -107,24 +107,12 @@ static const AVOption crop_options[] = {
 
 AVFILTER_DEFINE_CLASS(crop);
 
-static av_cold int init(AVFilterContext *ctx, const char *args)
-{
-    CropContext *crop = ctx->priv;
-    static const char *shorthand[] = { "w", "h", "x", "y", "keep_aspect", NULL };
-
-    crop->class = &crop_class;
-    av_opt_set_defaults(crop);
-
-    return av_opt_set_from_string(crop, args, shorthand, "=", ":");
-}
-
 static av_cold void uninit(AVFilterContext *ctx)
 {
     CropContext *crop = ctx->priv;
 
     av_expr_free(crop->x_pexpr); crop->x_pexpr = NULL;
     av_expr_free(crop->y_pexpr); crop->y_pexpr = NULL;
-    av_opt_free(crop);
 }
 
 static int query_formats(AVFilterContext *ctx)
@@ -348,6 +336,8 @@ static const AVFilterPad avfilter_vf_crop_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] = { "w", "h", "x", "y", "keep_aspect", NULL };
+
 AVFilter avfilter_vf_crop = {
     .name      = "crop",
     .description = NULL_IF_CONFIG_SMALL("Crop the input video to width:height:x:y."),
@@ -355,10 +345,10 @@ AVFilter avfilter_vf_crop = {
     .priv_size = sizeof(CropContext),
 
     .query_formats = query_formats,
-    .init          = init,
     .uninit        = uninit,
 
     .inputs    = avfilter_vf_crop_inputs,
     .outputs   = avfilter_vf_crop_outputs,
     .priv_class = &crop_class,
+    .shorthand = shorthand,
 };
diff --git a/libavfilter/vf_decimate.c b/libavfilter/vf_decimate.c
index f0e49c993f..630f3ba492 100644
--- a/libavfilter/vf_decimate.c
+++ b/libavfilter/vf_decimate.c
@@ -132,14 +132,6 @@ static int decimate_frame(AVFilterContext *ctx,
 static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     DecimateContext *decimate = ctx->priv;
-    static const char *shorthand[] = { "max", "hi", "lo", "frac", NULL };
-    int ret;
-
-    decimate->class = &decimate_class;
-    av_opt_set_defaults(decimate);
-
-    if ((ret = av_opt_set_from_string(decimate, args, shorthand, "=", ":")) < 0)
-        return ret;
 
     av_log(ctx, AV_LOG_VERBOSE, "max_drop_count:%d hi:%d lo:%d frac:%f\n",
            decimate->max_drop_count, decimate->hi, decimate->lo, decimate->frac);
@@ -157,7 +149,6 @@ static av_cold void uninit(AVFilterContext *ctx)
     DecimateContext *decimate = ctx->priv;
     av_frame_free(&decimate->ref);
     avcodec_close(decimate->avctx);
-    av_opt_free(decimate);
     av_freep(&decimate->avctx);
 }
 
@@ -251,6 +242,8 @@ static const AVFilterPad decimate_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] = { "max", "hi", "lo", "frac", NULL };
+
 AVFilter avfilter_vf_decimate = {
     .name        = "decimate",
     .description = NULL_IF_CONFIG_SMALL("Remove near-duplicate frames."),
@@ -262,4 +255,5 @@ AVFilter avfilter_vf_decimate = {
     .inputs        = decimate_inputs,
     .outputs       = decimate_outputs,
     .priv_class    = &decimate_class,
+    .shorthand     = shorthand,
 };
diff --git a/libavfilter/vf_delogo.c b/libavfilter/vf_delogo.c
index 4c0670d136..159f69fc09 100644
--- a/libavfilter/vf_delogo.c
+++ b/libavfilter/vf_delogo.c
@@ -171,14 +171,6 @@ static int query_formats(AVFilterContext *ctx)
 static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     DelogoContext *delogo = ctx->priv;
-    int ret = 0;
-    static const char *shorthand[] = { "x", "y", "w", "h", "band", NULL };
-
-    delogo->class = &delogo_class;
-    av_opt_set_defaults(delogo);
-
-    if ((ret = av_opt_set_from_string(delogo, args, shorthand, "=", ":")) < 0)
-        return ret;
 
 #define CHECK_UNSET_OPT(opt)                                            \
     if (delogo->opt == -1) {                                            \
@@ -267,6 +259,8 @@ static const AVFilterPad avfilter_vf_delogo_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] = { "x", "y", "w", "h", "band", NULL };
+
 AVFilter avfilter_vf_delogo = {
     .name          = "delogo",
     .description   = NULL_IF_CONFIG_SMALL("Remove logo from input video."),
@@ -277,4 +271,5 @@ AVFilter avfilter_vf_delogo = {
     .inputs    = avfilter_vf_delogo_inputs,
     .outputs   = avfilter_vf_delogo_outputs,
     .priv_class = &delogo_class,
+    .shorthand = shorthand,
 };
diff --git a/libavfilter/vf_drawbox.c b/libavfilter/vf_drawbox.c
index 41601b9fab..b831182c8b 100644
--- a/libavfilter/vf_drawbox.c
+++ b/libavfilter/vf_drawbox.c
@@ -68,14 +68,6 @@ static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     DrawBoxContext *drawbox = ctx->priv;
     uint8_t rgba_color[4];
-    static const char *shorthand[] = { "x", "y", "w", "h", "color", "thickness", NULL };
-    int ret;
-
-    drawbox->class = &drawbox_class;
-    av_opt_set_defaults(drawbox);
-
-    if ((ret = av_opt_set_from_string(drawbox, args, shorthand, "=", ":")) < 0)
-        return ret;
 
     if (!strcmp(drawbox->color_str, "invert"))
         drawbox->invert_color = 1;
@@ -92,12 +84,6 @@ static av_cold int init(AVFilterContext *ctx, const char *args)
     return 0;
 }
 
-static av_cold void uninit(AVFilterContext *ctx)
-{
-    DrawBoxContext *drawbox = ctx->priv;
-    av_opt_free(drawbox);
-}
-
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
@@ -185,15 +171,17 @@ static const AVFilterPad avfilter_vf_drawbox_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] = { "x", "y", "w", "h", "color", "thickness", NULL };
+
 AVFilter avfilter_vf_drawbox = {
     .name      = "drawbox",
     .description = NULL_IF_CONFIG_SMALL("Draw a colored box on the input video."),
     .priv_size = sizeof(DrawBoxContext),
     .init      = init,
-    .uninit    = uninit,
 
     .query_formats   = query_formats,
     .inputs    = avfilter_vf_drawbox_inputs,
     .outputs   = avfilter_vf_drawbox_outputs,
     .priv_class = &drawbox_class,
+    .shorthand = shorthand,
 };
diff --git a/libavfilter/vf_fade.c b/libavfilter/vf_fade.c
index a74e6d8e96..8036672133 100644
--- a/libavfilter/vf_fade.c
+++ b/libavfilter/vf_fade.c
@@ -78,14 +78,6 @@ AVFILTER_DEFINE_CLASS(fade);
 static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     FadeContext *fade = ctx->priv;
-    static const char *shorthand[] = { "type", "start_frame", "nb_frames", NULL };
-    int ret;
-
-    fade->class = &fade_class;
-    av_opt_set_defaults(fade);
-
-    if ((ret = av_opt_set_from_string(fade, args, shorthand, "=", ":")) < 0)
-        return ret;
 
     fade->fade_per_frame = (1 << 16) / fade->nb_frames;
     if (!strcmp(fade->type, "in"))
@@ -106,13 +98,6 @@ static av_cold int init(AVFilterContext *ctx, const char *args)
     return 0;
 }
 
-static av_cold void uninit(AVFilterContext *ctx)
-{
-    FadeContext *fade = ctx->priv;
-
-    av_opt_free(fade);
-}
-
 static int query_formats(AVFilterContext *ctx)
 {
     static const enum AVPixelFormat pix_fmts[] = {
@@ -247,15 +232,17 @@ static const AVFilterPad avfilter_vf_fade_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] = { "type", "start_frame", "nb_frames", NULL };
+
 AVFilter avfilter_vf_fade = {
     .name          = "fade",
     .description   = NULL_IF_CONFIG_SMALL("Fade in/out input video."),
     .init          = init,
-    .uninit        = uninit,
     .priv_size     = sizeof(FadeContext),
     .query_formats = query_formats,
 
     .inputs    = avfilter_vf_fade_inputs,
     .outputs   = avfilter_vf_fade_outputs,
     .priv_class = &fade_class,
+    .shorthand = shorthand,
 };
diff --git a/libavfilter/vf_fps.c b/libavfilter/vf_fps.c
index 3394252687..5952538133 100644
--- a/libavfilter/vf_fps.c
+++ b/libavfilter/vf_fps.c
@@ -74,20 +74,12 @@ AVFILTER_DEFINE_CLASS(fps);
 static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     FPSContext *s = ctx->priv;
-    const char *shorthand[] = { "fps", "round", NULL };
     int ret;
 
-    s->class = &fps_class;
-    av_opt_set_defaults(s);
-
-    if ((ret = av_opt_set_from_string(s, args, shorthand, "=", ":")) < 0)
-        return ret;
-
     if ((ret = av_parse_video_rate(&s->framerate, s->fps)) < 0) {
         av_log(ctx, AV_LOG_ERROR, "Error parsing framerate %s.\n", s->fps);
         return ret;
     }
-    av_opt_free(s);
 
     if (!(s->fifo = av_fifo_alloc(2*sizeof(AVFrame*))))
         return AVERROR(ENOMEM);
@@ -288,6 +280,8 @@ static const AVFilterPad avfilter_vf_fps_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] = { "fps", "round", NULL };
+
 AVFilter avfilter_vf_fps = {
     .name        = "fps",
     .description = NULL_IF_CONFIG_SMALL("Force constant framerate"),
@@ -300,4 +294,5 @@ AVFilter avfilter_vf_fps = {
     .inputs    = avfilter_vf_fps_inputs,
     .outputs   = avfilter_vf_fps_outputs,
     .priv_class = &fps_class,
+    .shorthand = shorthand,
 };
diff --git a/libavfilter/vf_pad.c b/libavfilter/vf_pad.c
index 4e1e3b0703..ed979bbe10 100644
--- a/libavfilter/vf_pad.c
+++ b/libavfilter/vf_pad.c
@@ -111,14 +111,6 @@ AVFILTER_DEFINE_CLASS(pad);
 static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     PadContext *pad = ctx->priv;
-    static const char *shorthand[] = { "width", "height", "x", "y", "color", NULL };
-    int ret;
-
-    pad->class = &pad_class;
-    av_opt_set_defaults(pad);
-
-    if ((ret = av_opt_set_from_string(pad, args, shorthand, "=", ":")) < 0)
-        return ret;
 
     if (av_parse_color(pad->rgba_color, pad->color_str, -1, ctx) < 0)
         return AVERROR(EINVAL);
@@ -126,12 +118,6 @@ static av_cold int init(AVFilterContext *ctx, const char *args)
     return 0;
 }
 
-static av_cold void uninit(AVFilterContext *ctx)
-{
-    PadContext *pad = ctx->priv;
-    av_opt_free(pad);
-}
-
 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
@@ -416,17 +402,19 @@ static const AVFilterPad avfilter_vf_pad_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] = { "width", "height", "x", "y", "color", NULL };
+
 AVFilter avfilter_vf_pad = {
     .name          = "pad",
     .description   = NULL_IF_CONFIG_SMALL("Pad input image to width:height[:x:y[:color]] (default x and y: 0, default color: black)."),
 
     .priv_size     = sizeof(PadContext),
     .init          = init,
-    .uninit        = uninit,
     .query_formats = query_formats,
 
     .inputs    = avfilter_vf_pad_inputs,
 
     .outputs   = avfilter_vf_pad_outputs,
     .priv_class = &pad_class,
+    .shorthand = shorthand,
 };
diff --git a/libavfilter/vf_tile.c b/libavfilter/vf_tile.c
index 30c9809374..b45cbb81bb 100644
--- a/libavfilter/vf_tile.c
+++ b/libavfilter/vf_tile.c
@@ -65,14 +65,6 @@ AVFILTER_DEFINE_CLASS(tile);
 static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     TileContext *tile = ctx->priv;
-    static const char *shorthand[] = { "layout", "nb_frames", "margin", "padding", NULL };
-    int ret;
-
-    tile->class = &tile_class;
-    av_opt_set_defaults(tile);
-
-    if ((ret = av_opt_set_from_string(tile, args, shorthand, "=", ":")) < 0)
-        return ret;
 
     if (tile->w > REASONABLE_SIZE || tile->h > REASONABLE_SIZE) {
         av_log(ctx, AV_LOG_ERROR, "Tile size %ux%u is insane.\n",
@@ -243,6 +235,9 @@ static const AVFilterPad tile_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] =
+    { "layout", "nb_frames", "margin", "padding", NULL };
+
 AVFilter avfilter_vf_tile = {
     .name          = "tile",
     .description   = NULL_IF_CONFIG_SMALL("Tile several successive frames together."),
@@ -252,4 +247,5 @@ AVFilter avfilter_vf_tile = {
     .inputs        = tile_inputs,
     .outputs       = tile_outputs,
     .priv_class    = &tile_class,
+    .shorthand     = shorthand,
 };
diff --git a/libavfilter/vf_transpose.c b/libavfilter/vf_transpose.c
index aafb44efaf..ed870178e5 100644
--- a/libavfilter/vf_transpose.c
+++ b/libavfilter/vf_transpose.c
@@ -73,17 +73,6 @@ static const AVOption transpose_options[] = {
 
 AVFILTER_DEFINE_CLASS(transpose);
 
-static av_cold int init(AVFilterContext *ctx, const char *args)
-{
-    TransContext *trans = ctx->priv;
-    const char *shorthand[] = { "dir", "passthrough", NULL };
-
-    trans->class = &transpose_class;
-    av_opt_set_defaults(trans);
-
-    return av_opt_set_from_string(trans, args, shorthand, "=", ":");
-}
-
 static int query_formats(AVFilterContext *ctx)
 {
     AVFilterFormats *pix_fmts = NULL;
@@ -266,11 +255,12 @@ static const AVFilterPad avfilter_vf_transpose_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] = { "dir", "passthrough", NULL };
+
 AVFilter avfilter_vf_transpose = {
     .name      = "transpose",
     .description = NULL_IF_CONFIG_SMALL("Transpose input video."),
 
-    .init = init,
     .priv_size = sizeof(TransContext),
 
     .query_formats = query_formats,
@@ -278,4 +268,5 @@ AVFilter avfilter_vf_transpose = {
     .inputs    = avfilter_vf_transpose_inputs,
     .outputs   = avfilter_vf_transpose_outputs,
     .priv_class = &transpose_class,
+    .shorthand = shorthand,
 };
diff --git a/libavfilter/vf_unsharp.c b/libavfilter/vf_unsharp.c
index 0c084a88aa..84a14eefeb 100644
--- a/libavfilter/vf_unsharp.c
+++ b/libavfilter/vf_unsharp.c
@@ -169,18 +169,6 @@ static void set_filter_param(FilterParam *fp, int msize_x, int msize_y, double a
 static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     UnsharpContext *unsharp = ctx->priv;
-    static const char *shorthand[] = {
-        "luma_msize_x", "luma_msize_y", "luma_amount",
-        "chroma_msize_x", "chroma_msize_y", "chroma_amount",
-        NULL
-    };
-    int ret;
-
-    unsharp->class = &unsharp_class;
-    av_opt_set_defaults(unsharp);
-
-    if ((ret = av_opt_set_from_string(unsharp, args, shorthand, "=", ":")) < 0)
-        return ret;
 
     set_filter_param(&unsharp->luma,   unsharp->luma_msize_x,   unsharp->luma_msize_y,   unsharp->luma_amount);
     set_filter_param(&unsharp->chroma, unsharp->chroma_msize_x, unsharp->chroma_msize_y, unsharp->chroma_amount);
@@ -256,7 +244,6 @@ static av_cold void uninit(AVFilterContext *ctx)
 
     free_filter_param(&unsharp->luma);
     free_filter_param(&unsharp->chroma);
-    av_opt_free(unsharp);
 }
 
 static int filter_frame(AVFilterLink *link, AVFrame *in)
@@ -300,6 +287,12 @@ static const AVFilterPad avfilter_vf_unsharp_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] = {
+    "luma_msize_x", "luma_msize_y", "luma_amount",
+    "chroma_msize_x", "chroma_msize_y", "chroma_amount",
+    NULL
+};
+
 AVFilter avfilter_vf_unsharp = {
     .name      = "unsharp",
     .description = NULL_IF_CONFIG_SMALL("Sharpen or blur the input video."),
@@ -315,4 +308,5 @@ AVFilter avfilter_vf_unsharp = {
     .outputs   = avfilter_vf_unsharp_outputs,
 
     .priv_class = &unsharp_class,
+    .shorthand = shorthand,
 };
diff --git a/libavfilter/vf_yadif.c b/libavfilter/vf_yadif.c
index 1ec51dfdc0..80076f7517 100644
--- a/libavfilter/vf_yadif.c
+++ b/libavfilter/vf_yadif.c
@@ -377,7 +377,6 @@ static av_cold void uninit(AVFilterContext *ctx)
     av_frame_free(&yadif->prev);
     av_frame_free(&yadif->cur );
     av_frame_free(&yadif->next);
-    av_opt_free(yadif);
 }
 
 static int query_formats(AVFilterContext *ctx)
@@ -424,14 +423,6 @@ static int query_formats(AVFilterContext *ctx)
 static av_cold int init(AVFilterContext *ctx, const char *args)
 {
     YADIFContext *yadif = ctx->priv;
-    static const char *shorthand[] = { "mode", "parity", "deint", NULL };
-    int ret;
-
-    yadif->class = &yadif_class;
-    av_opt_set_defaults(yadif);
-
-    if ((ret = av_opt_set_from_string(yadif, args, shorthand, "=", ":")) < 0)
-        return ret;
 
     av_log(ctx, AV_LOG_VERBOSE, "mode:%d parity:%d deint:%d\n",
            yadif->mode, yadif->parity, yadif->deint);
@@ -491,6 +482,8 @@ static const AVFilterPad avfilter_vf_yadif_outputs[] = {
     { NULL }
 };
 
+static const char *const shorthand[] = { "mode", "parity", "deint", NULL };
+
 AVFilter avfilter_vf_yadif = {
     .name          = "yadif",
     .description   = NULL_IF_CONFIG_SMALL("Deinterlace the input image."),
@@ -504,4 +497,5 @@ AVFilter avfilter_vf_yadif = {
     .outputs   = avfilter_vf_yadif_outputs,
 
     .priv_class = &yadif_class,
+    .shorthand = shorthand,
 };
diff --git a/libavformat/concatdec.c b/libavformat/concatdec.c
index 380ad4383f..5359ad149d 100644
--- a/libavformat/concatdec.c
+++ b/libavformat/concatdec.c
@@ -37,6 +37,7 @@ typedef struct {
     unsigned nb_files;
     AVFormatContext *avf;
     int safe;
+    int seekable;
 } ConcatContext;
 
 static int concat_probe(AVProbeData *probe)
@@ -128,6 +129,8 @@ static int open_file(AVFormatContext *avf, unsigned fileno)
     ConcatFile *file = &cat->files[fileno];
     int ret;
 
+    if (cat->avf)
+        avformat_close_input(&cat->avf);
     if ((ret = avformat_open_input(&cat->avf, file->url, NULL, NULL)) < 0 ||
         (ret = avformat_find_stream_info(cat->avf, NULL)) < 0) {
         av_log(avf, AV_LOG_ERROR, "Impossible to open '%s'\n", file->url);
@@ -223,8 +226,10 @@ static int concat_read_header(AVFormatContext *avf)
             break;
         time += cat->files[i].duration;
     }
-    if (i == cat->nb_files)
+    if (i == cat->nb_files) {
         avf->duration = time;
+        cat->seekable = 1;
+    }
 
     if ((ret = open_file(avf, 0)) < 0)
         FAIL(ret);
@@ -257,7 +262,6 @@ static int open_next_file(AVFormatContext *avf)
 
     if (++fileno >= cat->nb_files)
         return AVERROR_EOF;
-    avformat_close_input(&cat->avf);
     return open_file(avf, fileno);
 }
 
@@ -282,6 +286,95 @@ static int concat_read_packet(AVFormatContext *avf, AVPacket *pkt)
     return ret;
 }
 
+static void rescale_interval(AVRational tb_in, AVRational tb_out,
+                             int64_t *min_ts, int64_t *ts, int64_t *max_ts)
+{
+    *ts     = av_rescale_q    (*    ts, tb_in, tb_out);
+    *min_ts = av_rescale_q_rnd(*min_ts, tb_in, tb_out,
+                               AV_ROUND_UP   | AV_ROUND_PASS_MINMAX);
+    *max_ts = av_rescale_q_rnd(*max_ts, tb_in, tb_out,
+                               AV_ROUND_DOWN | AV_ROUND_PASS_MINMAX);
+}
+
+static int try_seek(AVFormatContext *avf, int stream,
+                    int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
+{
+    ConcatContext *cat = avf->priv_data;
+    int64_t t0 = cat->cur_file->start_time - cat->avf->start_time;
+
+    ts -= t0;
+    min_ts = min_ts == INT64_MIN ? INT64_MIN : min_ts - t0;
+    max_ts = max_ts == INT64_MAX ? INT64_MAX : max_ts - t0;
+    if (stream >= 0) {
+        if (stream >= cat->avf->nb_streams)
+            return AVERROR(EIO);
+        rescale_interval(AV_TIME_BASE_Q, cat->avf->streams[stream]->time_base,
+                         &min_ts, &ts, &max_ts);
+    }
+    return avformat_seek_file(cat->avf, stream, min_ts, ts, max_ts, flags);
+}
+
+static int real_seek(AVFormatContext *avf, int stream,
+                     int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
+{
+    ConcatContext *cat = avf->priv_data;
+    int ret, left, right;
+
+    if (stream >= 0) {
+        if (stream >= avf->nb_streams)
+            return AVERROR(EINVAL);
+        rescale_interval(avf->streams[stream]->time_base, AV_TIME_BASE_Q,
+                         &min_ts, &ts, &max_ts);
+    }
+
+    left  = 0;
+    right = cat->nb_files;
+    while (right - left > 1) {
+        int mid = (left + right) / 2;
+        if (ts < cat->files[mid].start_time)
+            right = mid;
+        else
+            left  = mid;
+    }
+
+    if ((ret = open_file(avf, left)) < 0)
+        return ret;
+
+    ret = try_seek(avf, stream, min_ts, ts, max_ts, flags);
+    if (ret < 0 && !(flags & AVSEEK_FLAG_BACKWARD) &&
+        left < cat->nb_files - 1 &&
+        cat->files[left + 1].start_time < max_ts) {
+        if ((ret = open_file(avf, left + 1)) < 0)
+            return ret;
+        ret = try_seek(avf, stream, min_ts, ts, max_ts, flags);
+    }
+    return ret;
+}
+
+static int concat_seek(AVFormatContext *avf, int stream,
+                       int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
+{
+    ConcatContext *cat = avf->priv_data;
+    ConcatFile *cur_file_saved = cat->cur_file;
+    AVFormatContext *cur_avf_saved = cat->avf;
+    int ret;
+
+    if (!cat->seekable)
+        return AVERROR(ESPIPE); /* XXX: can we use it? */
+    if (flags & (AVSEEK_FLAG_BYTE | AVSEEK_FLAG_FRAME))
+        return AVERROR(ENOSYS);
+    cat->avf = NULL;
+    if ((ret = real_seek(avf, stream, min_ts, ts, max_ts, flags)) < 0) {
+        if (cat->avf)
+            avformat_close_input(&cat->avf);
+        cat->avf      = cur_avf_saved;
+        cat->cur_file = cur_file_saved;
+    } else {
+        avformat_close_input(&cur_avf_saved);
+    }
+    return ret;
+}
+
 #define OFFSET(x) offsetof(ConcatContext, x)
 #define DEC AV_OPT_FLAG_DECODING_PARAM
 
@@ -307,5 +400,6 @@ AVInputFormat ff_concat_demuxer = {
     .read_header    = concat_read_header,
     .read_packet    = concat_read_packet,
     .read_close     = concat_read_close,
+    .read_seek2     = concat_seek,
     .priv_class     = &concat_class,
 };
diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c
index 5387b092e4..f36f0db727 100644
--- a/libavformat/mpeg.c
+++ b/libavformat/mpeg.c
@@ -805,6 +805,8 @@ end:
     return ret;
 }
 
+#define FAIL(r) do { ret = r; goto fail; } while (0)
+
 static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     MpegDemuxContext *vobsub = s->priv_data;
@@ -838,7 +840,7 @@ static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
 
         ret = mpegps_read_pes_header(vobsub->sub_ctx, NULL, &startcode, &pts, &dts);
         if (ret < 0)
-            return ret;
+            FAIL(ret);
         to_read = ret & 0xffff;
 
         /* this prevents reads above the current packet */
@@ -855,7 +857,7 @@ static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
 
         ret = av_grow_packet(pkt, to_read);
         if (ret < 0)
-            return ret;
+            FAIL(ret);
 
         n = avio_read(pb, pkt->data + (pkt->size - to_read), to_read);
         if (n < to_read)
@@ -870,7 +872,12 @@ static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
     pkt->pos = idx_pkt.pos;
     pkt->stream_index = idx_pkt.stream_index;
 
+    av_free_packet(&idx_pkt);
     return 0;
+
+fail:
+    av_free_packet(&idx_pkt);
+    return ret;
 }
 
 static int vobsub_read_seek(AVFormatContext *s, int stream_index,
diff --git a/libavutil/opt.c b/libavutil/opt.c
index 2d149da2d8..a2cdcb4a17 100644
--- a/libavutil/opt.c
+++ b/libavutil/opt.c
@@ -77,6 +77,7 @@ static int read_number(const AVOption *o, void *dst, double *num, int *den, int6
     case AV_OPT_TYPE_PIXEL_FMT:
     case AV_OPT_TYPE_SAMPLE_FMT:
     case AV_OPT_TYPE_INT:       *intnum = *(int         *)dst;return 0;
+    case AV_OPT_TYPE_DURATION:
     case AV_OPT_TYPE_INT64:     *intnum = *(int64_t     *)dst;return 0;
     case AV_OPT_TYPE_FLOAT:     *num    = *(float       *)dst;return 0;
     case AV_OPT_TYPE_DOUBLE:    *num    = *(double      *)dst;return 0;
@@ -101,6 +102,7 @@ static int write_number(void *obj, const AVOption *o, void *dst, double num, int
     case AV_OPT_TYPE_PIXEL_FMT:
     case AV_OPT_TYPE_SAMPLE_FMT:
     case AV_OPT_TYPE_INT:   *(int       *)dst= llrint(num/den)*intnum; break;
+    case AV_OPT_TYPE_DURATION:
     case AV_OPT_TYPE_INT64: *(int64_t   *)dst= llrint(num/den)*intnum; break;
     case AV_OPT_TYPE_FLOAT: *(float     *)dst= num*intnum/den;         break;
     case AV_OPT_TYPE_DOUBLE:*(double    *)dst= num*intnum/den;         break;
@@ -256,7 +258,8 @@ int av_opt_set(void *obj, const char *name, const char *val, int search_flags)
         return AVERROR_OPTION_NOT_FOUND;
     if (!val && (o->type != AV_OPT_TYPE_STRING &&
                  o->type != AV_OPT_TYPE_PIXEL_FMT && o->type != AV_OPT_TYPE_SAMPLE_FMT &&
-                 o->type != AV_OPT_TYPE_IMAGE_SIZE && o->type != AV_OPT_TYPE_VIDEO_RATE))
+                 o->type != AV_OPT_TYPE_IMAGE_SIZE && o->type != AV_OPT_TYPE_VIDEO_RATE &&
+                 o->type != AV_OPT_TYPE_DURATION))
         return AVERROR(EINVAL);
 
     dst = ((uint8_t*)target_obj) + o->offset;
@@ -319,6 +322,15 @@ int av_opt_set(void *obj, const char *name, const char *val, int search_flags)
         }
         *(enum AVSampleFormat *)dst = ret;
         return 0;
+    case AV_OPT_TYPE_DURATION:
+        if (!val) {
+            *(int64_t *)dst = 0;
+            return 0;
+        } else {
+            if ((ret = av_parse_time(dst, val, 1)) < 0)
+                av_log(obj, AV_LOG_ERROR, "Unable to parse option value \"%s\" as duration\n", val);
+            return ret;
+        }
     }
 
     av_log(obj, AV_LOG_ERROR, "Invalid option type.\n");
@@ -556,6 +568,7 @@ int av_opt_get(void *obj, const char *name, int search_flags, uint8_t **out_val)
     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;
@@ -597,6 +610,12 @@ int av_opt_get(void *obj, const char *name, int search_flags, uint8_t **out_val)
     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"));
         break;
+    case AV_OPT_TYPE_DURATION:
+        i64 = *(int64_t *)dst;
+        ret = snprintf(buf, sizeof(buf), "%"PRIi64"d:%02d:%02d.%06d",
+                       i64 / 3600000000, (int)((i64 / 60000000) % 60),
+                       (int)((i64 / 1000000) % 60), (int)(i64 % 1000000));
+        break;
     default:
         return AVERROR(EINVAL);
     }
@@ -861,6 +880,9 @@ static void opt_list(void *obj, void *av_log_obj, const char *unit,
             case AV_OPT_TYPE_SAMPLE_FMT:
                 av_log(av_log_obj, AV_LOG_INFO, "%-12s ", "<sample_fmt>");
                 break;
+            case AV_OPT_TYPE_DURATION:
+                av_log(av_log_obj, AV_LOG_INFO, "%-12s ", "<duration>");
+                break;
             case AV_OPT_TYPE_CONST:
             default:
                 av_log(av_log_obj, AV_LOG_INFO, "%-12s ", "");
@@ -937,6 +959,7 @@ void av_opt_set_defaults2(void *s, int mask, int flags)
             case AV_OPT_TYPE_FLAGS:
             case AV_OPT_TYPE_INT:
             case AV_OPT_TYPE_INT64:
+            case AV_OPT_TYPE_DURATION:
                 av_opt_set_int(s, opt->name, opt->default_val.i64, 0);
             break;
             case AV_OPT_TYPE_DOUBLE:
@@ -1300,6 +1323,7 @@ int av_opt_query_ranges_default(AVOptionRanges **ranges_arg, void *obj, const ch
     case AV_OPT_TYPE_SAMPLE_FMT:
     case AV_OPT_TYPE_FLOAT:
     case AV_OPT_TYPE_DOUBLE:
+    case AV_OPT_TYPE_DURATION:
         break;
     case AV_OPT_TYPE_STRING:
         range->component_min = 0;
@@ -1365,6 +1389,7 @@ typedef struct TestContext
     int w, h;
     enum AVPixelFormat pix_fmt;
     enum AVSampleFormat sample_fmt;
+    int64_t duration;
 } TestContext;
 
 #define OFFSET(x) offsetof(TestContext, x)
@@ -1386,6 +1411,7 @@ static const AVOption test_options[]= {
 {"pix_fmt",  "set pixfmt",     OFFSET(pix_fmt),  AV_OPT_TYPE_PIXEL_FMT, {.i64 = AV_PIX_FMT_NONE}, -1, AV_PIX_FMT_NB-1},
 {"sample_fmt", "set samplefmt", OFFSET(sample_fmt), AV_OPT_TYPE_SAMPLE_FMT, {.i64 = AV_SAMPLE_FMT_NONE}, -1, AV_SAMPLE_FMT_NB-1},
 {"video_rate", "set videorate", OFFSET(video_rate), AV_OPT_TYPE_VIDEO_RATE,  {.str = "25"}, 0,     0                   },
+{"duration", "set duration",   OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX},
 {NULL},
 };
 
@@ -1441,6 +1467,9 @@ int main(void)
             "video_rate=30000/1001",
             "video_rate=30/1.001",
             "video_rate=bogus",
+            "duration=bogus",
+            "duration=123.45",
+            "duration=1\\:23\\:45.67",
         };
 
         test_ctx.class = &test_class;
diff --git a/libavutil/opt.h b/libavutil/opt.h
index b36aebe1ed..30f729e447 100644
--- a/libavutil/opt.h
+++ b/libavutil/opt.h
@@ -231,6 +231,7 @@ enum AVOptionType{
     AV_OPT_TYPE_PIXEL_FMT  = MKBETAG('P','F','M','T'),
     AV_OPT_TYPE_SAMPLE_FMT = MKBETAG('S','F','M','T'),
     AV_OPT_TYPE_VIDEO_RATE = MKBETAG('V','R','A','T'), ///< offset must point to AVRational
+    AV_OPT_TYPE_DURATION   = MKBETAG('D','U','R',' '),
 #if FF_API_OLD_AVOPTIONS
     FF_OPT_TYPE_FLAGS = 0,
     FF_OPT_TYPE_INT,
diff --git a/libavutil/version.h b/libavutil/version.h
index 0619eb9203..1c163cae59 100644
--- a/libavutil/version.h
+++ b/libavutil/version.h
@@ -75,7 +75,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  52
-#define LIBAVUTIL_VERSION_MINOR  21
+#define LIBAVUTIL_VERSION_MINOR  22
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \