| /* |
| * 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/avstring.h" |
| #include "libavutil/common.h" |
| #include "libavutil/bprint.h" |
| #include "libavutil/intreadwrite.h" |
| #include "libavutil/mem.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 |
| |
| typedef struct { |
| char *font; |
| int fontsize; |
| int color; |
| int back_color; |
| int bold; |
| int italic; |
| int 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 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 { |
| StyleBox **s; |
| StyleBox *s_temp; |
| HighlightBox h; |
| HilightcolorBox c; |
| FontRecord **ftab; |
| FontRecord *ftab_temp; |
| TextWrapBox w; |
| MovTextDefault d; |
| uint8_t box_flags; |
| uint16_t style_entries, ftab_entries; |
| uint64_t tracksize; |
| int size_var; |
| int count_s, count_f; |
| } MovTextContext; |
| |
| typedef struct { |
| uint32_t type; |
| size_t base_size; |
| int (*decode)(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt); |
| } Box; |
| |
| static void mov_text_cleanup(MovTextContext *m) |
| { |
| int i; |
| if (m->box_flags & STYL_BOX) { |
| for(i = 0; i < m->count_s; i++) { |
| av_freep(&m->s[i]); |
| } |
| av_freep(&m->s); |
| } |
| } |
| |
| static void mov_text_cleanup_ftab(MovTextContext *m) |
| { |
| int i; |
| if (m->ftab_temp) |
| av_freep(&m->ftab_temp->font); |
| av_freep(&m->ftab_temp); |
| if (m->ftab) { |
| for(i = 0; i < m->count_f; i++) { |
| av_freep(&m->ftab[i]->font); |
| av_freep(&m->ftab[i]); |
| } |
| } |
| av_freep(&m->ftab); |
| } |
| |
| static int mov_text_tx3g(AVCodecContext *avctx, MovTextContext *m) |
| { |
| uint8_t *tx3g_ptr = avctx->extradata; |
| int i, box_size, font_length; |
| int8_t v_align, h_align; |
| int style_fontID; |
| StyleBox s_default; |
| |
| m->count_f = 0; |
| m->ftab_entries = 0; |
| box_size = BOX_SIZE_INITIAL; /* Size till ftab_entries */ |
| if (avctx->extradata_size < box_size) |
| return -1; |
| |
| // Display Flags |
| tx3g_ptr += 4; |
| // Alignment |
| h_align = *tx3g_ptr++; |
| v_align = *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 = AV_RB24(tx3g_ptr); |
| tx3g_ptr += 4; |
| // BoxRecord |
| tx3g_ptr += 8; |
| // StyleRecord |
| tx3g_ptr += 4; |
| // fontID |
| style_fontID = AV_RB16(tx3g_ptr); |
| tx3g_ptr += 2; |
| // face-style-flags |
| s_default.style_flag = *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 = *tx3g_ptr++; |
| // Primary color |
| m->d.color = AV_RB24(tx3g_ptr); |
| tx3g_ptr += 4; |
| // FontRecord |
| // FontRecord Size |
| tx3g_ptr += 4; |
| // ftab |
| tx3g_ptr += 4; |
| |
| m->ftab_entries = AV_RB16(tx3g_ptr); |
| tx3g_ptr += 2; |
| |
| for (i = 0; i < m->ftab_entries; i++) { |
| |
| box_size += 3; |
| if (avctx->extradata_size < box_size) { |
| mov_text_cleanup_ftab(m); |
| m->ftab_entries = 0; |
| return -1; |
| } |
| m->ftab_temp = av_mallocz(sizeof(*m->ftab_temp)); |
| if (!m->ftab_temp) { |
| mov_text_cleanup_ftab(m); |
| return AVERROR(ENOMEM); |
| } |
| m->ftab_temp->fontID = AV_RB16(tx3g_ptr); |
| tx3g_ptr += 2; |
| font_length = *tx3g_ptr++; |
| |
| box_size = box_size + font_length; |
| if (avctx->extradata_size < box_size) { |
| mov_text_cleanup_ftab(m); |
| m->ftab_entries = 0; |
| return -1; |
| } |
| m->ftab_temp->font = av_malloc(font_length + 1); |
| if (!m->ftab_temp->font) { |
| mov_text_cleanup_ftab(m); |
| return AVERROR(ENOMEM); |
| } |
| memcpy(m->ftab_temp->font, tx3g_ptr, font_length); |
| m->ftab_temp->font[font_length] = '\0'; |
| av_dynarray_add(&m->ftab, &m->count_f, m->ftab_temp); |
| if (!m->ftab) { |
| mov_text_cleanup_ftab(m); |
| return AVERROR(ENOMEM); |
| } |
| m->ftab_temp = NULL; |
| tx3g_ptr = tx3g_ptr + font_length; |
| } |
| for (i = 0; i < m->ftab_entries; i++) { |
| if (style_fontID == m->ftab[i]->fontID) |
| m->d.font = m->ftab[i]->font; |
| } |
| return 0; |
| } |
| |
| static int decode_twrp(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) |
| { |
| m->box_flags |= TWRP_BOX; |
| m->w.wrap_flag = *tsmb++; |
| return 0; |
| } |
| |
| static int decode_hlit(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) |
| { |
| m->box_flags |= HLIT_BOX; |
| m->h.hlit_start = AV_RB16(tsmb); |
| tsmb += 2; |
| m->h.hlit_end = AV_RB16(tsmb); |
| tsmb += 2; |
| return 0; |
| } |
| |
| static int decode_hclr(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) |
| { |
| m->box_flags |= HCLR_BOX; |
| memcpy(m->c.hlit_color, tsmb, 4); |
| tsmb += 4; |
| return 0; |
| } |
| |
| static int decode_styl(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) |
| { |
| int i; |
| m->style_entries = AV_RB16(tsmb); |
| tsmb += 2; |
| // A single style record is of length 12 bytes. |
| if (m->tracksize + m->size_var + 2 + m->style_entries * 12 > avpkt->size) |
| return -1; |
| |
| m->box_flags |= STYL_BOX; |
| for(i = 0; i < m->style_entries; i++) { |
| m->s_temp = av_malloc(sizeof(*m->s_temp)); |
| if (!m->s_temp) { |
| mov_text_cleanup(m); |
| return AVERROR(ENOMEM); |
| } |
| m->s_temp->style_start = AV_RB16(tsmb); |
| tsmb += 2; |
| m->s_temp->style_end = AV_RB16(tsmb); |
| tsmb += 2; |
| m->s_temp->style_fontID = AV_RB16(tsmb); |
| tsmb += 2; |
| m->s_temp->style_flag = AV_RB8(tsmb); |
| tsmb++; |
| m->s_temp->fontsize = AV_RB8(tsmb); |
| av_dynarray_add(&m->s, &m->count_s, m->s_temp); |
| if(!m->s) { |
| mov_text_cleanup(m); |
| return AVERROR(ENOMEM); |
| } |
| tsmb++; |
| // text-color-rgba |
| tsmb += 4; |
| } |
| 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); |
| |
| static int text_to_ass(AVBPrint *buf, const char *text, const char *text_end, |
| MovTextContext *m) |
| { |
| int i = 0; |
| int j = 0; |
| int text_pos = 0; |
| |
| 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) { |
| if (m->box_flags & STYL_BOX) { |
| for (i = 0; i < m->style_entries; i++) { |
| if (m->s[i]->style_flag && text_pos == m->s[i]->style_end) { |
| av_bprintf(buf, "{\\r}"); |
| } |
| } |
| for (i = 0; i < m->style_entries; i++) { |
| if (m->s[i]->style_flag && text_pos == m->s[i]->style_start) { |
| if (m->s[i]->style_flag & STYLE_FLAG_BOLD) |
| av_bprintf(buf, "{\\b1}"); |
| if (m->s[i]->style_flag & STYLE_FLAG_ITALIC) |
| av_bprintf(buf, "{\\i1}"); |
| if (m->s[i]->style_flag & STYLE_FLAG_UNDERLINE) |
| av_bprintf(buf, "{\\u1}"); |
| av_bprintf(buf, "{\\fs%d}", m->s[i]->fontsize); |
| for (j = 0; j < m->ftab_entries; j++) { |
| if (m->s[i]->style_fontID == m->ftab[j]->fontID) |
| av_bprintf(buf, "{\\fn%s}", m->ftab[j]->font); |
| } |
| } |
| } |
| } |
| 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&H000000&}"); |
| } else { |
| av_bprintf(buf, "{\\1c&HFFFFFF&}{\\2c&H000000&}"); |
| } |
| } |
| } |
| |
| switch (*text) { |
| case '\r': |
| break; |
| case '\n': |
| av_bprintf(buf, "\\N"); |
| break; |
| default: |
| av_bprint_chars(buf, *text, 1); |
| break; |
| } |
| text++; |
| 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) { |
| return ff_ass_subtitle_header(avctx, m->d.font, m->d.fontsize, m->d.color, |
| 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, ts_start, ts_end; |
| AVBPrint buf; |
| char *ptr = avpkt->data; |
| char *end; |
| int text_length, tsmb_type, ret_tsmb; |
| uint64_t tsmb_size; |
| const uint8_t *tsmb; |
| |
| 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; |
| |
| ts_start = av_rescale_q(avpkt->pts, |
| avctx->time_base, |
| (AVRational){1,100}); |
| ts_end = av_rescale_q(avpkt->pts + avpkt->duration, |
| avctx->time_base, |
| (AVRational){1,100}); |
| |
| tsmb_size = 0; |
| m->tracksize = 2 + text_length; |
| m->style_entries = 0; |
| m->box_flags = 0; |
| m->count_s = 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 (m->tracksize + tsmb_size > avpkt->size) |
| break; |
| |
| for (size_t 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, m); |
| mov_text_cleanup(m); |
| } else |
| text_to_ass(&buf, ptr, end, m); |
| |
| ret = ff_ass_add_rect_bprint(sub, &buf, ts_start, ts_end - ts_start); |
| 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); |
| return 0; |
| } |
| |
| 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), |
| .init = mov_text_init, |
| .decode = mov_text_decode_frame, |
| .close = mov_text_decode_close, |
| }; |
