| /* |
| * 3GPP TS 26.245 Timed Text decoder |
| * 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 "avcodec.h" |
| #include "ass.h" |
| #include "libavutil/opt.h" |
| #include "libavutil/avstring.h" |
| #include "libavutil/common.h" |
| #include "libavutil/bprint.h" |
| #include "libavutil/intreadwrite.h" |
| #include "libavutil/mem.h" |
| #include "bytestream.h" |
| |
| #define STYLE_FLAG_BOLD (1<<0) |
| #define STYLE_FLAG_ITALIC (1<<1) |
| #define STYLE_FLAG_UNDERLINE (1<<2) |
| |
| #define BOX_SIZE_INITIAL 40 |
| |
| #define STYL_BOX (1<<0) |
| #define HLIT_BOX (1<<1) |
| #define HCLR_BOX (1<<2) |
| #define TWRP_BOX (1<<3) |
| |
| #define BOTTOM_LEFT 1 |
| #define BOTTOM_CENTER 2 |
| #define BOTTOM_RIGHT 3 |
| #define MIDDLE_LEFT 4 |
| #define MIDDLE_CENTER 5 |
| #define MIDDLE_RIGHT 6 |
| #define TOP_LEFT 7 |
| #define TOP_CENTER 8 |
| #define TOP_RIGHT 9 |
| |
| #define RGB_TO_BGR(c) (((c) & 0xff) << 16 | ((c) & 0xff00) | (((c) >> 16) & 0xff)) |
| |
| typedef struct { |
| uint16_t fontID; |
| const char *font; |
| uint8_t fontsize; |
| int color; |
| uint8_t alpha; |
| int back_color; |
| uint8_t back_alpha; |
| uint8_t bold; |
| uint8_t italic; |
| uint8_t underline; |
| int alignment; |
| } MovTextDefault; |
| |
| typedef struct { |
| uint16_t fontID; |
| char *font; |
| } FontRecord; |
| |
| typedef struct { |
| uint16_t style_start; |
| uint16_t style_end; |
| uint8_t style_flag; |
| uint8_t bold; |
| uint8_t italic; |
| uint8_t underline; |
| int color; |
| uint8_t alpha; |
| uint8_t fontsize; |
| uint16_t style_fontID; |
| } StyleBox; |
| |
| typedef struct { |
| uint16_t hlit_start; |
| uint16_t hlit_end; |
| } HighlightBox; |
| |
| typedef struct { |
| uint8_t hlit_color[4]; |
| } HilightcolorBox; |
| |
| typedef struct { |
| uint8_t wrap_flag; |
| } TextWrapBox; |
| |
| typedef struct { |
| AVClass *class; |
| StyleBox *s; |
| HighlightBox h; |
| HilightcolorBox c; |
| FontRecord *ftab; |
| TextWrapBox w; |
| MovTextDefault d; |
| uint8_t box_flags; |
| uint16_t style_entries, ftab_entries; |
| uint64_t tracksize; |
| int size_var; |
| int readorder; |
| int frame_width; |
| int frame_height; |
| } MovTextContext; |
| |
| typedef struct { |
| uint32_t type; |
| size_t base_size; |
| int (*decode)(const uint8_t *tsmb, MovTextContext *m, const AVPacket *avpkt); |
| } Box; |
| |
| static void mov_text_cleanup(MovTextContext *m) |
| { |
| if (m->box_flags & STYL_BOX) { |
| av_freep(&m->s); |
| m->style_entries = 0; |
| } |
| } |
| |
| static void mov_text_cleanup_ftab(MovTextContext *m) |
| { |
| for (unsigned i = 0; i < m->ftab_entries; i++) |
| av_freep(&m->ftab[i].font); |
| av_freep(&m->ftab); |
| m->ftab_entries = 0; |
| } |
| |
| static int mov_text_tx3g(AVCodecContext *avctx, MovTextContext *m) |
| { |
| const uint8_t *tx3g_ptr = avctx->extradata; |
| int i, j = -1, font_length, remaining = avctx->extradata_size - BOX_SIZE_INITIAL; |
| int8_t v_align, h_align; |
| unsigned ftab_entries; |
| StyleBox s_default; |
| |
| m->ftab_entries = 0; |
| if (remaining < 0) |
| return -1; |
| |
| // Display Flags |
| tx3g_ptr += 4; |
| // Alignment |
| h_align = bytestream_get_byte(&tx3g_ptr); |
| v_align = bytestream_get_byte(&tx3g_ptr); |
| if (h_align == 0) { |
| if (v_align == 0) |
| m->d.alignment = TOP_LEFT; |
| if (v_align == 1) |
| m->d.alignment = MIDDLE_LEFT; |
| if (v_align == -1) |
| m->d.alignment = BOTTOM_LEFT; |
| } |
| if (h_align == 1) { |
| if (v_align == 0) |
| m->d.alignment = TOP_CENTER; |
| if (v_align == 1) |
| m->d.alignment = MIDDLE_CENTER; |
| if (v_align == -1) |
| m->d.alignment = BOTTOM_CENTER; |
| } |
| if (h_align == -1) { |
| if (v_align == 0) |
| m->d.alignment = TOP_RIGHT; |
| if (v_align == 1) |
| m->d.alignment = MIDDLE_RIGHT; |
| if (v_align == -1) |
| m->d.alignment = BOTTOM_RIGHT; |
| } |
| // Background Color |
| m->d.back_color = bytestream_get_be24(&tx3g_ptr); |
| m->d.back_alpha = bytestream_get_byte(&tx3g_ptr); |
| // BoxRecord |
| tx3g_ptr += 8; |
| // StyleRecord |
| tx3g_ptr += 4; |
| // fontID |
| m->d.fontID = bytestream_get_be16(&tx3g_ptr); |
| // face-style-flags |
| s_default.style_flag = bytestream_get_byte(&tx3g_ptr); |
| m->d.bold = !!(s_default.style_flag & STYLE_FLAG_BOLD); |
| m->d.italic = !!(s_default.style_flag & STYLE_FLAG_ITALIC); |
| m->d.underline = !!(s_default.style_flag & STYLE_FLAG_UNDERLINE); |
| // fontsize |
| m->d.fontsize = bytestream_get_byte(&tx3g_ptr); |
| // Primary color |
| m->d.color = bytestream_get_be24(&tx3g_ptr); |
| m->d.alpha = bytestream_get_byte(&tx3g_ptr); |
| // FontRecord |
| // FontRecord Size |
| tx3g_ptr += 4; |
| // ftab |
| tx3g_ptr += 4; |
| |
| // In case of broken header, init default font |
| m->d.font = ASS_DEFAULT_FONT; |
| |
| ftab_entries = bytestream_get_be16(&tx3g_ptr); |
| if (!ftab_entries) |
| return 0; |
| remaining -= 3 * ftab_entries; |
| if (remaining < 0) |
| return AVERROR_INVALIDDATA; |
| m->ftab = av_calloc(ftab_entries, sizeof(*m->ftab)); |
| if (!m->ftab) |
| return AVERROR(ENOMEM); |
| m->ftab_entries = ftab_entries; |
| |
| for (i = 0; i < m->ftab_entries; i++) { |
| m->ftab[i].fontID = bytestream_get_be16(&tx3g_ptr); |
| if (m->ftab[i].fontID == m->d.fontID) |
| j = i; |
| font_length = bytestream_get_byte(&tx3g_ptr); |
| |
| remaining -= font_length; |
| if (remaining < 0) { |
| mov_text_cleanup_ftab(m); |
| return -1; |
| } |
| m->ftab[i].font = av_malloc(font_length + 1); |
| if (!m->ftab[i].font) { |
| mov_text_cleanup_ftab(m); |
| return AVERROR(ENOMEM); |
| } |
| bytestream_get_buffer(&tx3g_ptr, m->ftab[i].font, font_length); |
| m->ftab[i].font[font_length] = '\0'; |
| } |
| if (j >= 0) |
| m->d.font = m->ftab[j].font; |
| return 0; |
| } |
| |
| static int decode_twrp(const uint8_t *tsmb, MovTextContext *m, const AVPacket *avpkt) |
| { |
| m->box_flags |= TWRP_BOX; |
| m->w.wrap_flag = bytestream_get_byte(&tsmb); |
| return 0; |
| } |
| |
| static int decode_hlit(const uint8_t *tsmb, MovTextContext *m, const AVPacket *avpkt) |
| { |
| m->box_flags |= HLIT_BOX; |
| m->h.hlit_start = bytestream_get_be16(&tsmb); |
| m->h.hlit_end = bytestream_get_be16(&tsmb); |
| return 0; |
| } |
| |
| static int decode_hclr(const uint8_t *tsmb, MovTextContext *m, const AVPacket *avpkt) |
| { |
| m->box_flags |= HCLR_BOX; |
| bytestream_get_buffer(&tsmb, m->c.hlit_color, 4); |
| return 0; |
| } |
| |
| static int decode_styl(const uint8_t *tsmb, MovTextContext *m, const AVPacket *avpkt) |
| { |
| int i; |
| int style_entries = bytestream_get_be16(&tsmb); |
| StyleBox *tmp; |
| |
| // A single style record is of length 12 bytes. |
| if (m->tracksize + m->size_var + 2 + style_entries * 12 > avpkt->size) |
| return -1; |
| |
| tmp = av_realloc_array(m->s, style_entries, sizeof(*m->s)); |
| if (!tmp) |
| return AVERROR(ENOMEM); |
| m->s = tmp; |
| m->style_entries = style_entries; |
| |
| m->box_flags |= STYL_BOX; |
| for(i = 0; i < m->style_entries; i++) { |
| StyleBox *style = &m->s[i]; |
| |
| style->style_start = bytestream_get_be16(&tsmb); |
| style->style_end = bytestream_get_be16(&tsmb); |
| if ( style->style_end < style->style_start |
| || (i && style->style_start < m->s[i - 1].style_end)) { |
| mov_text_cleanup(m); |
| return AVERROR(ENOMEM); |
| } |
| if (style->style_start == style->style_end) { |
| /* Skip this style as it applies to no character */ |
| tsmb += 8; |
| m->style_entries--; |
| i--; |
| continue; |
| } |
| |
| style->style_fontID = bytestream_get_be16(&tsmb); |
| style->style_flag = bytestream_get_byte(&tsmb); |
| style->bold = !!(style->style_flag & STYLE_FLAG_BOLD); |
| style->italic = !!(style->style_flag & STYLE_FLAG_ITALIC); |
| style->underline = !!(style->style_flag & STYLE_FLAG_UNDERLINE); |
| style->fontsize = bytestream_get_byte(&tsmb); |
| style->color = bytestream_get_be24(&tsmb); |
| style->alpha = bytestream_get_byte(&tsmb); |
| } |
| return 0; |
| } |
| |
| static const Box box_types[] = { |
| { MKBETAG('s','t','y','l'), 2, decode_styl }, |
| { MKBETAG('h','l','i','t'), 4, decode_hlit }, |
| { MKBETAG('h','c','l','r'), 4, decode_hclr }, |
| { MKBETAG('t','w','r','p'), 1, decode_twrp } |
| }; |
| |
| const static size_t box_count = FF_ARRAY_ELEMS(box_types); |
| |
| // Return byte length of the UTF-8 sequence starting at text[0]. 0 on error. |
| static int get_utf8_length_at(const char *text, const char *text_end) |
| { |
| const char *start = text; |
| int err = 0; |
| uint32_t c; |
| GET_UTF8(c, text < text_end ? (uint8_t)*text++ : (err = 1, 0), goto error;); |
| if (err) |
| goto error; |
| return text - start; |
| error: |
| return 0; |
| } |
| |
| static int text_to_ass(AVBPrint *buf, const char *text, const char *text_end, |
| AVCodecContext *avctx) |
| { |
| MovTextContext *m = avctx->priv_data; |
| int i = 0; |
| int text_pos = 0; |
| int entry = 0; |
| int color = m->d.color; |
| |
| if (text < text_end && m->box_flags & TWRP_BOX) { |
| if (m->w.wrap_flag == 1) { |
| av_bprintf(buf, "{\\q1}"); /* End of line wrap */ |
| } else { |
| av_bprintf(buf, "{\\q2}"); /* No wrap */ |
| } |
| } |
| |
| while (text < text_end) { |
| int len; |
| |
| if ((m->box_flags & STYL_BOX) && entry < m->style_entries) { |
| const StyleBox *style = &m->s[entry]; |
| if (text_pos == style->style_end) { |
| av_bprintf(buf, "{\\r}"); |
| color = m->d.color; |
| entry++; |
| style++; |
| } |
| if (entry < m->style_entries && text_pos == style->style_start) { |
| if (style->bold ^ m->d.bold) |
| av_bprintf(buf, "{\\b%d}", style->bold); |
| if (style->italic ^ m->d.italic) |
| av_bprintf(buf, "{\\i%d}", style->italic); |
| if (style->underline ^ m->d.underline) |
| av_bprintf(buf, "{\\u%d}", style->underline); |
| if (style->fontsize != m->d.fontsize) |
| av_bprintf(buf, "{\\fs%d}", style->fontsize); |
| if (style->style_fontID != m->d.fontID) |
| for (i = 0; i < m->ftab_entries; i++) { |
| if (style->style_fontID == m->ftab[i].fontID) |
| av_bprintf(buf, "{\\fn%s}", m->ftab[i].font); |
| } |
| if (m->d.color != style->color) { |
| color = style->color; |
| av_bprintf(buf, "{\\1c&H%X&}", RGB_TO_BGR(color)); |
| } |
| if (m->d.alpha != style->alpha) |
| av_bprintf(buf, "{\\1a&H%02X&}", 255 - style->alpha); |
| } |
| } |
| if (m->box_flags & HLIT_BOX) { |
| if (text_pos == m->h.hlit_start) { |
| /* If hclr box is present, set the secondary color to the color |
| * specified. Otherwise, set primary color to white and secondary |
| * color to black. These colors will come from TextSampleModifier |
| * boxes in future and inverse video technique for highlight will |
| * be implemented. |
| */ |
| if (m->box_flags & HCLR_BOX) { |
| av_bprintf(buf, "{\\2c&H%02x%02x%02x&}", m->c.hlit_color[2], |
| m->c.hlit_color[1], m->c.hlit_color[0]); |
| } else { |
| av_bprintf(buf, "{\\1c&H000000&}{\\2c&HFFFFFF&}"); |
| } |
| } |
| if (text_pos == m->h.hlit_end) { |
| if (m->box_flags & HCLR_BOX) { |
| av_bprintf(buf, "{\\2c&H%X&}", RGB_TO_BGR(m->d.color)); |
| } else { |
| av_bprintf(buf, "{\\1c&H%X&}{\\2c&H%X&}", |
| RGB_TO_BGR(color), RGB_TO_BGR(m->d.color)); |
| } |
| } |
| } |
| |
| len = get_utf8_length_at(text, text_end); |
| if (len < 1) { |
| av_log(avctx, AV_LOG_ERROR, "invalid UTF-8 byte in subtitle\n"); |
| len = 1; |
| } |
| switch (*text) { |
| case '\r': |
| break; |
| case '\n': |
| av_bprintf(buf, "\\N"); |
| break; |
| default: |
| av_bprint_append_data(buf, text, len); |
| break; |
| } |
| text += len; |
| text_pos++; |
| } |
| |
| return 0; |
| } |
| |
| static int mov_text_init(AVCodecContext *avctx) { |
| /* |
| * TODO: Handle the default text style. |
| * NB: Most players ignore styles completely, with the result that |
| * it's very common to find files where the default style is broken |
| * and respecting it results in a worse experience than ignoring it. |
| */ |
| int ret; |
| MovTextContext *m = avctx->priv_data; |
| ret = mov_text_tx3g(avctx, m); |
| if (ret == 0) { |
| if (!m->frame_width || !m->frame_height) { |
| m->frame_width = ASS_DEFAULT_PLAYRESX; |
| m->frame_height = ASS_DEFAULT_PLAYRESY; |
| } |
| return ff_ass_subtitle_header_full(avctx, |
| m->frame_width, m->frame_height, |
| m->d.font, m->d.fontsize, |
| (255U - m->d.alpha) << 24 | RGB_TO_BGR(m->d.color), |
| (255U - m->d.alpha) << 24 | RGB_TO_BGR(m->d.color), |
| (255U - m->d.back_alpha) << 24 | RGB_TO_BGR(m->d.back_color), |
| (255U - m->d.back_alpha) << 24 | RGB_TO_BGR(m->d.back_color), |
| m->d.bold, m->d.italic, m->d.underline, |
| ASS_DEFAULT_BORDERSTYLE, m->d.alignment); |
| } else |
| return ff_ass_subtitle_header_default(avctx); |
| } |
| |
| static int mov_text_decode_frame(AVCodecContext *avctx, |
| void *data, int *got_sub_ptr, AVPacket *avpkt) |
| { |
| AVSubtitle *sub = data; |
| MovTextContext *m = avctx->priv_data; |
| int ret; |
| AVBPrint buf; |
| char *ptr = avpkt->data; |
| char *end; |
| int text_length, tsmb_type, ret_tsmb; |
| uint64_t tsmb_size; |
| const uint8_t *tsmb; |
| size_t i; |
| |
| if (!ptr || avpkt->size < 2) |
| return AVERROR_INVALIDDATA; |
| |
| /* |
| * A packet of size two with value zero is an empty subtitle |
| * used to mark the end of the previous non-empty subtitle. |
| * We can just drop them here as we have duration information |
| * already. If the value is non-zero, then it's technically a |
| * bad packet. |
| */ |
| if (avpkt->size == 2) |
| return AV_RB16(ptr) == 0 ? 0 : AVERROR_INVALIDDATA; |
| |
| /* |
| * The first two bytes of the packet are the length of the text string |
| * In complex cases, there are style descriptors appended to the string |
| * so we can't just assume the packet size is the string size. |
| */ |
| text_length = AV_RB16(ptr); |
| end = ptr + FFMIN(2 + text_length, avpkt->size); |
| ptr += 2; |
| |
| mov_text_cleanup(m); |
| |
| tsmb_size = 0; |
| m->tracksize = 2 + text_length; |
| m->style_entries = 0; |
| m->box_flags = 0; |
| // Note that the spec recommends lines be no longer than 2048 characters. |
| av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED); |
| if (text_length + 2 != avpkt->size) { |
| while (m->tracksize + 8 <= avpkt->size) { |
| // A box is a minimum of 8 bytes. |
| tsmb = ptr + m->tracksize - 2; |
| tsmb_size = AV_RB32(tsmb); |
| tsmb += 4; |
| tsmb_type = AV_RB32(tsmb); |
| tsmb += 4; |
| |
| if (tsmb_size == 1) { |
| if (m->tracksize + 16 > avpkt->size) |
| break; |
| tsmb_size = AV_RB64(tsmb); |
| tsmb += 8; |
| m->size_var = 16; |
| } else |
| m->size_var = 8; |
| //size_var is equal to 8 or 16 depending on the size of box |
| |
| if (tsmb_size == 0) { |
| av_log(avctx, AV_LOG_ERROR, "tsmb_size is 0\n"); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| if (tsmb_size > avpkt->size - m->tracksize) |
| break; |
| |
| for (i = 0; i < box_count; i++) { |
| if (tsmb_type == box_types[i].type) { |
| if (m->tracksize + m->size_var + box_types[i].base_size > avpkt->size) |
| break; |
| ret_tsmb = box_types[i].decode(tsmb, m, avpkt); |
| if (ret_tsmb == -1) |
| break; |
| } |
| } |
| m->tracksize = m->tracksize + tsmb_size; |
| } |
| text_to_ass(&buf, ptr, end, avctx); |
| mov_text_cleanup(m); |
| } else |
| text_to_ass(&buf, ptr, end, avctx); |
| |
| ret = ff_ass_add_rect(sub, buf.str, m->readorder++, 0, NULL, NULL); |
| av_bprint_finalize(&buf, NULL); |
| if (ret < 0) |
| return ret; |
| *got_sub_ptr = sub->num_rects > 0; |
| return avpkt->size; |
| } |
| |
| static int mov_text_decode_close(AVCodecContext *avctx) |
| { |
| MovTextContext *m = avctx->priv_data; |
| mov_text_cleanup_ftab(m); |
| mov_text_cleanup(m); |
| return 0; |
| } |
| |
| static void mov_text_flush(AVCodecContext *avctx) |
| { |
| MovTextContext *m = avctx->priv_data; |
| if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP)) |
| m->readorder = 0; |
| } |
| |
| #define OFFSET(x) offsetof(MovTextContext, x) |
| #define FLAGS AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_SUBTITLE_PARAM |
| static const AVOption options[] = { |
| { "width", "Frame width, usually video width", OFFSET(frame_width), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS }, |
| { "height", "Frame height, usually video height", OFFSET(frame_height), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS }, |
| { NULL }, |
| }; |
| |
| static const AVClass mov_text_decoder_class = { |
| .class_name = "MOV text decoder", |
| .item_name = av_default_item_name, |
| .option = options, |
| .version = LIBAVUTIL_VERSION_INT, |
| }; |
| |
| AVCodec ff_movtext_decoder = { |
| .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), |
| .priv_class = &mov_text_decoder_class, |
| .init = mov_text_init, |
| .decode = mov_text_decode_frame, |
| .close = mov_text_decode_close, |
| .flush = mov_text_flush, |
| }; |