diff options
Diffstat (limited to 'libavcodec/movtextenc.c')
| -rw-r--r-- | libavcodec/movtextenc.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/libavcodec/movtextenc.c b/libavcodec/movtextenc.c new file mode 100644 index 0000000..1b8f454 --- /dev/null +++ b/libavcodec/movtextenc.c @@ -0,0 +1,165 @@ +/* + * 3GPP TS 26.245 Timed Text encoder + * Copyright (c) 2012 Philip Langdale <philipl@overt.org> + * + * 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/avassert.h" +#include "libavutil/avstring.h" +#include "libavutil/intreadwrite.h" +#include "ass_split.h" +#include "ass.h" + +typedef struct { + ASSSplitContext *ass_ctx; + char buffer[2048]; + char *ptr; + char *end; +} MovTextContext; + + +static av_cold int mov_text_encode_init(AVCodecContext *avctx) +{ + /* + * For now, we'll use a fixed default style. When we add styling + * support, this will be generated from the ASS style. + */ + static const uint8_t text_sample_entry[] = { + 0x00, 0x00, 0x00, 0x00, // uint32_t displayFlags + 0x01, // int8_t horizontal-justification + 0xFF, // int8_t vertical-justification + 0x00, 0x00, 0x00, 0x00, // uint8_t background-color-rgba[4] + // BoxRecord { + 0x00, 0x00, // int16_t top + 0x00, 0x00, // int16_t left + 0x00, 0x00, // int16_t bottom + 0x00, 0x00, // int16_t right + // }; + // StyleRecord { + 0x00, 0x00, // uint16_t startChar + 0x00, 0x00, // uint16_t endChar + 0x00, 0x01, // uint16_t font-ID + 0x00, // uint8_t face-style-flags + 0x12, // uint8_t font-size + 0xFF, 0xFF, 0xFF, 0xFF, // uint8_t text-color-rgba[4] + // }; + // FontTableBox { + 0x00, 0x00, 0x00, 0x12, // uint32_t size + 'f', 't', 'a', 'b', // uint8_t name[4] + 0x00, 0x01, // uint16_t entry-count + // FontRecord { + 0x00, 0x01, // uint16_t font-ID + 0x05, // uint8_t font-name-length + 'S', 'e', 'r', 'i', 'f',// uint8_t font[font-name-length] + // }; + // }; + }; + + MovTextContext *s = avctx->priv_data; + + avctx->extradata_size = sizeof text_sample_entry; + avctx->extradata = av_mallocz(avctx->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE); + if (!avctx->extradata) + return AVERROR(ENOMEM); + + memcpy(avctx->extradata, text_sample_entry, avctx->extradata_size); + + s->ass_ctx = ff_ass_split(avctx->subtitle_header); + return s->ass_ctx ? 0 : AVERROR_INVALIDDATA; +} + +static void mov_text_text_cb(void *priv, const char *text, int len) +{ + MovTextContext *s = priv; + av_assert0(s->end >= s->ptr); + av_strlcpy(s->ptr, text, FFMIN(s->end - s->ptr, len + 1)); + s->ptr += FFMIN(s->end - s->ptr, len); +} + +static void mov_text_new_line_cb(void *priv, int forced) +{ + MovTextContext *s = priv; + av_assert0(s->end >= s->ptr); + av_strlcpy(s->ptr, "\n", FFMIN(s->end - s->ptr, 2)); + if (s->end > s->ptr) + s->ptr++; +} + +static const ASSCodesCallbacks mov_text_callbacks = { + .text = mov_text_text_cb, + .new_line = mov_text_new_line_cb, +}; + +static int mov_text_encode_frame(AVCodecContext *avctx, unsigned char *buf, + int bufsize, const AVSubtitle *sub) +{ + MovTextContext *s = avctx->priv_data; + ASSDialog *dialog; + int i, len, num; + + s->ptr = s->buffer; + s->end = s->ptr + sizeof(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++) { + ff_ass_split_override_codes(&mov_text_callbacks, s, dialog->text); + } + } + + if (s->ptr == s->buffer) + return 0; + + AV_WB16(buf, strlen(s->buffer)); + buf += 2; + + len = av_strlcpy(buf, s->buffer, bufsize - 2); + + if (len > bufsize-3) { + av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n"); + return AVERROR(EINVAL); + } + + return len + 2; +} + +static int mov_text_encode_close(AVCodecContext *avctx) +{ + MovTextContext *s = avctx->priv_data; + ff_ass_split_free(s->ass_ctx); + return 0; +} + +AVCodec ff_movtext_encoder = { + .name = "mov_text", + .long_name = NULL_IF_CONFIG_SMALL("3GPP Timed Text subtitle"), + .type = AVMEDIA_TYPE_SUBTITLE, + .id = AV_CODEC_ID_MOV_TEXT, + .priv_data_size = sizeof(MovTextContext), + .init = mov_text_encode_init, + .encode_sub = mov_text_encode_frame, + .close = mov_text_encode_close, +}; |
