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-rw-r--r--libavcodec/movtextdec.c548
1 files changed, 548 insertions, 0 deletions
diff --git a/libavcodec/movtextdec.c b/libavcodec/movtextdec.c
new file mode 100644
index 0000000000..bd19577724
--- /dev/null
+++ b/libavcodec/movtextdec.c
@@ -0,0 +1,548 @@
+/*
+ * 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;
+ int readorder;
+} 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);
+ m->count_s = 0;
+ m->style_entries = 0;
+ }
+}
+
+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;
+ int style_entries = AV_RB16(tsmb);
+ tsmb += 2;
+ // A single style record is of length 12 bytes.
+ if (m->tracksize + m->size_var + 2 + style_entries * 12 > avpkt->size)
+ return -1;
+
+ m->style_entries = style_entries;
+
+ 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;
+ 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;
+ 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 (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, m);
+ mov_text_cleanup(m);
+ } else
+ text_to_ass(&buf, ptr, end, m);
+
+ 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;
+}
+
+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,
+ .flush = mov_text_flush,
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-03 01:12:34 +0000