@@ -25,6 +25,7 @@ version <next>:

 - libx264 reference frames count limiting depending on level

 - native Opus decoder

 - display matrix export and rotation api

+- WebVTT encoder

 version 2.2:

@@ -1036,7 +1036,7 @@ performance on systems without hardware floating point support).

 @item TED Talks captions @tab @tab X @tab   @tab X

 @item VobSub (IDX+SUB) @tab   @tab X @tab   @tab X

 @item VPlayer          @tab   @tab X @tab   @tab X

-@item WebVTT           @tab X @tab X @tab   @tab X

+@item WebVTT           @tab X @tab X @tab X @tab X

 @item XSUB             @tab   @tab   @tab X @tab X

 @end multitable

@@ -487,6 +487,7 @@ OBJS-$(CONFIG_WAVPACK_ENCODER)         += wavpackenc.o

 OBJS-$(CONFIG_WEBP_DECODER)            += vp8.o vp8dsp.o vp56rac.o

 OBJS-$(CONFIG_WEBP_DECODER)            += webp.o exif.o tiff_common.o

 OBJS-$(CONFIG_WEBVTT_DECODER)          += webvttdec.o

+OBJS-$(CONFIG_WEBVTT_ENCODER)          += webvttenc.o

 OBJS-$(CONFIG_WMALOSSLESS_DECODER)     += wmalosslessdec.o wma_common.o

 OBJS-$(CONFIG_WMAPRO_DECODER)          += wmaprodec.o wma.o wma_common.o

 OBJS-$(CONFIG_WMAV1_DECODER)           += wmadec.o wma.o wma_common.o aactab.o

@@ -495,7 +495,7 @@ void avcodec_register_all(void)

     REGISTER_DECODER(SUBVIEWER1,        subviewer1);

     REGISTER_DECODER(TEXT,              text);

     REGISTER_DECODER(VPLAYER,           vplayer);

-    REGISTER_DECODER(WEBVTT,            webvtt);

+    REGISTER_ENCDEC (WEBVTT,            webvtt);

     REGISTER_ENCDEC (XSUB,              xsub);

     /* external libraries */

@@ -29,7 +29,7 @@

 #include "libavutil/version.h"

 #define LIBAVCODEC_VERSION_MAJOR 55

-#define LIBAVCODEC_VERSION_MINOR  64

+#define LIBAVCODEC_VERSION_MINOR  65

 #define LIBAVCODEC_VERSION_MICRO 100

 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \

new file mode 100644

@@ -0,0 +1,219 @@

+/*

+ * WebVTT subtitle encoder

+ * Copyright (c) 2010  Aurelien Jacobs <aurel@gnuage.org>

+ * Copyright (c) 2014  Aman Gupta <ffmpeg@tmm1.net>

+ *

+ * 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 <stdarg.h>

+#include "avcodec.h"

+#include "libavutil/avstring.h"

+#include "libavutil/bprint.h"

+#include "ass_split.h"

+#include "ass.h"

+

+#define WEBVTT_STACK_SIZE 64

+typedef struct {

+    AVCodecContext *avctx;

+    ASSSplitContext *ass_ctx;

+    AVBPrint buffer;

+    unsigned timestamp_end;

+    int count;

+    char stack[WEBVTT_STACK_SIZE];

+    int stack_ptr;

+} WebVTTContext;

+

+#ifdef __GNUC__

+__attribute__ ((__format__ (__printf__, 2, 3)))

+#endif

+static void webvtt_print(WebVTTContext *s, const char *str, ...)

+{

+    va_list vargs;

+    va_start(vargs, str);

+    av_vbprintf(&s->buffer, str, vargs);

+    va_end(vargs);

+}

+

+static int webvtt_stack_push(WebVTTContext *s, const char c)

+{

+    if (s->stack_ptr >= WEBVTT_STACK_SIZE)

+        return AVERROR(EOVERFLOW);

+    s->stack[s->stack_ptr++] = c;

+    return 0;

+}

+

+static char webvtt_stack_pop(WebVTTContext *s)

+{

+    if (s->stack_ptr <= 0)

+        return 0;

+    return s->stack[--s->stack_ptr];

+}

+

+static int webvtt_stack_find(WebVTTContext *s, const char c)

+{

+    int i;

+    for (i = s->stack_ptr-1; i >= 0; i--)

+        if (s->stack[i] == c)

+            break;

+    return i;

+}

+

+static void webvtt_close_tag(WebVTTContext *s, char tag)

+{

+    webvtt_print(s, "</%c>", tag);

+}

+

+static void webvtt_stack_push_pop(WebVTTContext *s, const char c, int close)

+{

+    if (close) {

+        int i = c ? webvtt_stack_find(s, c) : 0;

+        if (i < 0)

+            return;

+        while (s->stack_ptr != i)

+            webvtt_close_tag(s, webvtt_stack_pop(s));

+    } else if (webvtt_stack_push(s, c) < 0)

+        av_log(s->avctx, AV_LOG_ERROR, "tag stack overflow\n");

+}

+

+static void webvtt_style_apply(WebVTTContext *s, const char *style)

+{

+    ASSStyle *st = ff_ass_style_get(s->ass_ctx, style);

+    if (st) {

+        if (st->bold != ASS_DEFAULT_BOLD) {

+            webvtt_print(s, "<b>");

+            webvtt_stack_push(s, 'b');

+        }

+        if (st->italic != ASS_DEFAULT_ITALIC) {

+            webvtt_print(s, "<i>");

+            webvtt_stack_push(s, 'i');

+        }

+        if (st->underline != ASS_DEFAULT_UNDERLINE) {

+            webvtt_print(s, "<u>");

+            webvtt_stack_push(s, 'u');

+        }

+    }

+}

+

+static void webvtt_text_cb(void *priv, const char *text, int len)

+{

+    WebVTTContext *s = priv;

+    av_bprint_append_data(&s->buffer, text, len);

+}

+

+static void webvtt_new_line_cb(void *priv, int forced)

+{

+    webvtt_print(priv, "\n");

+}

+

+static void webvtt_style_cb(void *priv, char style, int close)

+{

+    if (style == 's') // strikethrough unsupported

+        return;

+

+    webvtt_stack_push_pop(priv, style, close);

+    if (!close)

+        webvtt_print(priv, "<%c>", style);

+}

+

+static void webvtt_cancel_overrides_cb(void *priv, const char *style)

+{

+    webvtt_stack_push_pop(priv, 0, 1);

+    webvtt_style_apply(priv, style);

+}

+

+static void webvtt_end_cb(void *priv)

+{

+    webvtt_stack_push_pop(priv, 0, 1);

+}

+

+static const ASSCodesCallbacks webvtt_callbacks = {

+    .text             = webvtt_text_cb,

+    .new_line         = webvtt_new_line_cb,

+    .style            = webvtt_style_cb,

+    .color            = NULL,

+    .font_name        = NULL,

+    .font_size        = NULL,

+    .alignment        = NULL,

+    .cancel_overrides = webvtt_cancel_overrides_cb,

+    .move             = NULL,

+    .end              = webvtt_end_cb,

+};

+

+static int webvtt_encode_frame(AVCodecContext *avctx,

+                               unsigned char *buf, int bufsize, const AVSubtitle *sub)

+{

+    WebVTTContext *s = avctx->priv_data;

+    ASSDialog *dialog;

+    int i, num;

+

+    av_bprint_clear(&s->buffer);

+

+    for (i=0; i<sub->num_rects; i++) {

+        if (sub->rects[i]->type != SUBTITLE_ASS) {

+            av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n");

+            return AVERROR(ENOSYS);

+        }

+

+        dialog = ff_ass_split_dialog(s->ass_ctx, sub->rects[i]->ass, 0, &num);

+        for (; dialog && num--; dialog++) {

+            webvtt_style_apply(s, dialog->style);

+            ff_ass_split_override_codes(&webvtt_callbacks, s, dialog->text);

+        }

+    }

+

+    if (!av_bprint_is_complete(&s->buffer))

+        return AVERROR(ENOMEM);

+    if (!s->buffer.len)

+        return 0;

+

+    if (s->buffer.len > bufsize) {

+        av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n");

+        return -1;

+    }

+    memcpy(buf, s->buffer.str, s->buffer.len);

+

+    return s->buffer.len;

+}

+

+static int webvtt_encode_close(AVCodecContext *avctx)

+{

+    WebVTTContext *s = avctx->priv_data;

+    ff_ass_split_free(s->ass_ctx);

+    av_bprint_finalize(&s->buffer, NULL);

+    return 0;

+}

+

+static av_cold int webvtt_encode_init(AVCodecContext *avctx)

+{

+    WebVTTContext *s = avctx->priv_data;

+    s->avctx = avctx;

+    s->ass_ctx = ff_ass_split(avctx->subtitle_header);

+    av_bprint_init(&s->buffer, 0, AV_BPRINT_SIZE_UNLIMITED);

+    return s->ass_ctx ? 0 : AVERROR_INVALIDDATA;

+}

+

+AVCodec ff_webvtt_encoder = {

+    .name           = "webvtt",

+    .long_name      = NULL_IF_CONFIG_SMALL("WebVTT subtitle"),

+    .type           = AVMEDIA_TYPE_SUBTITLE,

+    .id             = AV_CODEC_ID_WEBVTT,

+    .priv_data_size = sizeof(WebVTTContext),

+    .init           = webvtt_encode_init,

+    .encode_sub     = webvtt_encode_frame,

+    .close          = webvtt_encode_close,

+};

@@ -93,6 +93,7 @@ AVOutputFormat ff_webvtt_muxer = {

     .long_name         = NULL_IF_CONFIG_SMALL("WebVTT subtitle"),

     .extensions        = "vtt",

     .mime_type         = "text/vtt",

+    .flags             = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,

     .subtitle_codec    = AV_CODEC_ID_WEBVTT,

     .write_header      = webvtt_write_header,

     .write_packet      = webvtt_write_packet,

@@ -52,6 +52,9 @@ fate-sub-vplayer: CMD = md5 -i $(TARGET_SAMPLES)/sub/VPlayer_capability_tester.t

 FATE_SUBTITLES_ASS-$(call DEMDEC, WEBVTT, WEBVTT) += fate-sub-webvtt

 fate-sub-webvtt: CMD = md5 -i $(TARGET_SAMPLES)/sub/WebVTT_capability_tester.vtt -f ass

+FATE_SUBTITLES_ASS-$(call ENCMUX, WEBVTT, WEBVTT) += fate-sub-webvttenc

+fate-sub-webvttenc: CMD = md5 -i $(TARGET_SAMPLES)/sub/SubRip_capability_tester.srt -f webvtt

+

 FATE_SUBTITLES_ASS-$(call ALLYES, MICRODVD_DEMUXER MICRODVD_DECODER ICONV) += fate-sub-charenc

 fate-sub-charenc: CMD = md5 -sub_charenc cp1251 -i $(TARGET_SAMPLES)/sub/cp1251-subtitles.sub -f ass

new file mode 100644

@@ -0,0 +1 @@

+8683216a86e147a98f29dafee33a0987