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FFmpeg/libavcodec/libzvbi-teletextdec.c
wm4 b945fed629 avcodec: add metadata to identify wrappers and hardware decoders 
Explicitly identify decoder/encoder wrappers with a common name. This
saves API users from guessing by the name suffix. For example, they
don't have to guess that "h264_qsv" is the h264 QSV implementation, and
instead they can just check the AVCodec .codec and .wrapper_name fields.

Explicitly mark AVCodec entries that are hardware decoders or most
likely hardware decoders with new AV_CODEC_CAPs. The purpose is allowing
API users listing hardware decoders in a more generic way. The proposed
AVCodecHWConfig does not provide this information fully, because it's
concerned with decoder configuration, not information about the fact
whether the hardware is used or not.

AV_CODEC_CAP_HYBRID exists specifically for QSV, which can have software
implementations in case the hardware is not capable.

Based on a patch by Philip Langdale <philipl@overt.org>.

Merges Libav commit 47687a2f8a.
2017-12-14 19:37:56 +01:00

578 lines
20 KiB
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/*
* Teletext decoding for ffmpeg
* Copyright (c) 2005-2010, 2012 Wolfram Gloger
* Copyright (c) 2013 Marton Balint
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avcodec.h"
#include "libavcodec/ass.h"
#include "libavcodec/dvbtxt.h"
#include "libavutil/opt.h"
#include "libavutil/bprint.h"
#include "libavutil/internal.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/log.h"
#include <libzvbi.h>
#define TEXT_MAXSZ (25 * (56 + 1) * 4 + 2)
#define VBI_NB_COLORS 40
#define VBI_TRANSPARENT_BLACK 8
#define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
#define VBI_R(rgba) (((rgba) >> 0) & 0xFF)
#define VBI_G(rgba) (((rgba) >> 8) & 0xFF)
#define VBI_B(rgba) (((rgba) >> 16) & 0xFF)
#define VBI_A(rgba) (((rgba) >> 24) & 0xFF)
#define MAX_BUFFERED_PAGES 25
#define BITMAP_CHAR_WIDTH 12
#define BITMAP_CHAR_HEIGHT 10
#define MAX_SLICES 64
typedef struct TeletextPage
{
AVSubtitleRect *sub_rect;
int pgno;
int subno;
int64_t pts;
} TeletextPage;
typedef struct TeletextContext
{
AVClass *class;
char *pgno;
int x_offset;
int y_offset;
int format_id; /* 0 = bitmap, 1 = text/ass */
int chop_top;
int sub_duration; /* in msec */
int transparent_bg;
int opacity;
int chop_spaces;
int lines_processed;
TeletextPage *pages;
int nb_pages;
int64_t pts;
int handler_ret;
vbi_decoder * vbi;
#ifdef DEBUG
vbi_export * ex;
#endif
vbi_sliced sliced[MAX_SLICES];
int readorder;
} TeletextContext;
static int chop_spaces_utf8(const unsigned char* t, int len)
{
t += len;
while (len > 0) {
if (*--t != ' ' || (len-1 > 0 && *(t-1) & 0x80))
break;
--len;
}
return len;
}
static void subtitle_rect_free(AVSubtitleRect **sub_rect)
{
av_freep(&(*sub_rect)->data[0]);
av_freep(&(*sub_rect)->data[1]);
av_freep(&(*sub_rect)->ass);
av_freep(sub_rect);
}
static char *create_ass_text(TeletextContext *ctx, const char *text)
{
char *dialog;
AVBPrint buf;
av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
ff_ass_bprint_text_event(&buf, text, strlen(text), "", 0);
if (!av_bprint_is_complete(&buf)) {
av_bprint_finalize(&buf, NULL);
return NULL;
}
dialog = ff_ass_get_dialog(ctx->readorder++, 0, NULL, NULL, buf.str);
av_bprint_finalize(&buf, NULL);
return dialog;
}
/* Draw a page as text */
static int gen_sub_text(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
{
const char *in;
AVBPrint buf;
char *vbi_text = av_malloc(TEXT_MAXSZ);
int sz;
if (!vbi_text)
return AVERROR(ENOMEM);
sz = vbi_print_page_region(page, vbi_text, TEXT_MAXSZ-1, "UTF-8",
/*table mode*/ TRUE, FALSE,
0, chop_top,
page->columns, page->rows-chop_top);
if (sz <= 0) {
av_log(ctx, AV_LOG_ERROR, "vbi_print error\n");
av_free(vbi_text);
return AVERROR_EXTERNAL;
}
vbi_text[sz] = '\0';
in = vbi_text;
av_bprint_init(&buf, 0, TEXT_MAXSZ);
if (ctx->chop_spaces) {
for (;;) {
int nl, sz;
// skip leading spaces and newlines
in += strspn(in, " \n");
// compute end of row
for (nl = 0; in[nl]; ++nl)
if (in[nl] == '\n' && (nl==0 || !(in[nl-1] & 0x80)))
break;
if (!in[nl])
break;
// skip trailing spaces
sz = chop_spaces_utf8(in, nl);
av_bprint_append_data(&buf, in, sz);
av_bprintf(&buf, "\n");
in += nl;
}
} else {
av_bprintf(&buf, "%s\n", vbi_text);
}
av_free(vbi_text);
if (!av_bprint_is_complete(&buf)) {
av_bprint_finalize(&buf, NULL);
return AVERROR(ENOMEM);
}
if (buf.len) {
sub_rect->type = SUBTITLE_ASS;
sub_rect->ass = create_ass_text(ctx, buf.str);
if (!sub_rect->ass) {
av_bprint_finalize(&buf, NULL);
return AVERROR(ENOMEM);
}
av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass);
} else {
sub_rect->type = SUBTITLE_NONE;
}
av_bprint_finalize(&buf, NULL);
return 0;
}
static void fix_transparency(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page,
int chop_top, int resx, int resy)
{
int iy;
// Hack for transparency, inspired by VLC code...
for (iy = 0; iy < resy; iy++) {
uint8_t *pixel = sub_rect->data[0] + iy * sub_rect->linesize[0];
vbi_char *vc = page->text + (iy / BITMAP_CHAR_HEIGHT + chop_top) * page->columns;
vbi_char *vcnext = vc + page->columns;
for (; vc < vcnext; vc++) {
uint8_t *pixelnext = pixel + BITMAP_CHAR_WIDTH;
switch (vc->opacity) {
case VBI_TRANSPARENT_SPACE:
memset(pixel, VBI_TRANSPARENT_BLACK, BITMAP_CHAR_WIDTH);
break;
case VBI_OPAQUE:
if (!ctx->transparent_bg)
break;
case VBI_SEMI_TRANSPARENT:
if (ctx->opacity > 0) {
if (ctx->opacity < 255)
for(; pixel < pixelnext; pixel++)
if (*pixel == vc->background)
*pixel += VBI_NB_COLORS;
break;
}
case VBI_TRANSPARENT_FULL:
for(; pixel < pixelnext; pixel++)
if (*pixel == vc->background)
*pixel = VBI_TRANSPARENT_BLACK;
break;
}
pixel = pixelnext;
}
}
}
/* Draw a page as bitmap */
static int gen_sub_bitmap(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
{
int resx = page->columns * BITMAP_CHAR_WIDTH;
int resy = (page->rows - chop_top) * BITMAP_CHAR_HEIGHT;
uint8_t ci;
vbi_char *vc = page->text + (chop_top * page->columns);
vbi_char *vcend = page->text + (page->rows * page->columns);
for (; vc < vcend; vc++) {
if (vc->opacity != VBI_TRANSPARENT_SPACE)
break;
}
if (vc >= vcend) {
av_log(ctx, AV_LOG_DEBUG, "dropping empty page %3x\n", page->pgno);
sub_rect->type = SUBTITLE_NONE;
return 0;
}
sub_rect->data[0] = av_mallocz(resx * resy);
sub_rect->linesize[0] = resx;
if (!sub_rect->data[0])
return AVERROR(ENOMEM);
vbi_draw_vt_page_region(page, VBI_PIXFMT_PAL8,
sub_rect->data[0], sub_rect->linesize[0],
0, chop_top, page->columns, page->rows - chop_top,
/*reveal*/ 1, /*flash*/ 1);
fix_transparency(ctx, sub_rect, page, chop_top, resx, resy);
sub_rect->x = ctx->x_offset;
sub_rect->y = ctx->y_offset + chop_top * BITMAP_CHAR_HEIGHT;
sub_rect->w = resx;
sub_rect->h = resy;
sub_rect->nb_colors = ctx->opacity > 0 && ctx->opacity < 255 ? 2 * VBI_NB_COLORS : VBI_NB_COLORS;
sub_rect->data[1] = av_mallocz(AVPALETTE_SIZE);
if (!sub_rect->data[1]) {
av_freep(&sub_rect->data[0]);
return AVERROR(ENOMEM);
}
for (ci = 0; ci < VBI_NB_COLORS; ci++) {
int r, g, b, a;
r = VBI_R(page->color_map[ci]);
g = VBI_G(page->color_map[ci]);
b = VBI_B(page->color_map[ci]);
a = VBI_A(page->color_map[ci]);
((uint32_t *)sub_rect->data[1])[ci] = RGBA(r, g, b, a);
((uint32_t *)sub_rect->data[1])[ci + VBI_NB_COLORS] = RGBA(r, g, b, ctx->opacity);
ff_dlog(ctx, "palette %0x\n", ((uint32_t *)sub_rect->data[1])[ci]);
}
((uint32_t *)sub_rect->data[1])[VBI_TRANSPARENT_BLACK] = RGBA(0, 0, 0, 0);
((uint32_t *)sub_rect->data[1])[VBI_TRANSPARENT_BLACK + VBI_NB_COLORS] = RGBA(0, 0, 0, 0);
sub_rect->type = SUBTITLE_BITMAP;
return 0;
}
static void handler(vbi_event *ev, void *user_data)
{
TeletextContext *ctx = user_data;
TeletextPage *new_pages;
vbi_page page;
int res;
char pgno_str[12];
vbi_subno subno;
vbi_page_type vpt;
int chop_top;
char *lang;
snprintf(pgno_str, sizeof pgno_str, "%03x", ev->ev.ttx_page.pgno);
av_log(ctx, AV_LOG_DEBUG, "decoded page %s.%02x\n",
pgno_str, ev->ev.ttx_page.subno & 0xFF);
if (strcmp(ctx->pgno, "*") && !strstr(ctx->pgno, pgno_str))
return;
if (ctx->handler_ret < 0)
return;
res = vbi_fetch_vt_page(ctx->vbi, &page,
ev->ev.ttx_page.pgno,
ev->ev.ttx_page.subno,
VBI_WST_LEVEL_3p5, 25, TRUE);
if (!res)
return;
#ifdef DEBUG
fprintf(stderr, "\nSaving res=%d dy0=%d dy1=%d...\n",
res, page.dirty.y0, page.dirty.y1);
fflush(stderr);
if (!vbi_export_stdio(ctx->ex, stderr, &page))
fprintf(stderr, "failed: %s\n", vbi_export_errstr(ctx->ex));
#endif
vpt = vbi_classify_page(ctx->vbi, ev->ev.ttx_page.pgno, &subno, &lang);
chop_top = ctx->chop_top ||
((page.rows > 1) && (vpt == VBI_SUBTITLE_PAGE));
av_log(ctx, AV_LOG_DEBUG, "%d x %d page chop:%d\n",
page.columns, page.rows, chop_top);
if (ctx->nb_pages < MAX_BUFFERED_PAGES) {
if ((new_pages = av_realloc_array(ctx->pages, ctx->nb_pages + 1, sizeof(TeletextPage)))) {
TeletextPage *cur_page = new_pages + ctx->nb_pages;
ctx->pages = new_pages;
cur_page->sub_rect = av_mallocz(sizeof(*cur_page->sub_rect));
cur_page->pts = ctx->pts;
cur_page->pgno = ev->ev.ttx_page.pgno;
cur_page->subno = ev->ev.ttx_page.subno;
if (cur_page->sub_rect) {
res = (ctx->format_id == 0) ?
gen_sub_bitmap(ctx, cur_page->sub_rect, &page, chop_top) :
gen_sub_text (ctx, cur_page->sub_rect, &page, chop_top);
if (res < 0) {
av_freep(&cur_page->sub_rect);
ctx->handler_ret = res;
} else {
ctx->pages[ctx->nb_pages++] = *cur_page;
}
} else {
ctx->handler_ret = AVERROR(ENOMEM);
}
} else {
ctx->handler_ret = AVERROR(ENOMEM);
}
} else {
//TODO: If multiple packets contain more than one page, pages may got queued up, and this may happen...
av_log(ctx, AV_LOG_ERROR, "Buffered too many pages, dropping page %s.\n", pgno_str);
ctx->handler_ret = AVERROR(ENOSYS);
}
vbi_unref_page(&page);
}
static int slice_to_vbi_lines(TeletextContext *ctx, uint8_t* buf, int size)
{
int lines = 0;
while (size >= 2 && lines < MAX_SLICES) {
int data_unit_id = buf[0];
int data_unit_length = buf[1];
if (data_unit_length + 2 > size)
return AVERROR_INVALIDDATA;
if (ff_data_unit_id_is_teletext(data_unit_id)) {
if (data_unit_length != 0x2c)
return AVERROR_INVALIDDATA;
else {
int line_offset = buf[2] & 0x1f;
int field_parity = buf[2] & 0x20;
int i;
ctx->sliced[lines].id = VBI_SLICED_TELETEXT_B;
ctx->sliced[lines].line = (line_offset > 0 ? (line_offset + (field_parity ? 0 : 313)) : 0);
for (i = 0; i < 42; i++)
ctx->sliced[lines].data[i] = vbi_rev8(buf[4 + i]);
lines++;
}
}
size -= data_unit_length + 2;
buf += data_unit_length + 2;
}
if (size)
av_log(ctx, AV_LOG_WARNING, "%d bytes remained after slicing data\n", size);
return lines;
}
static int teletext_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *pkt)
{
TeletextContext *ctx = avctx->priv_data;
AVSubtitle *sub = data;
int ret = 0;
int j;
if (!ctx->vbi) {
if (!(ctx->vbi = vbi_decoder_new()))
return AVERROR(ENOMEM);
if (!vbi_event_handler_register(ctx->vbi, VBI_EVENT_TTX_PAGE, handler, ctx)) {
vbi_decoder_delete(ctx->vbi);
ctx->vbi = NULL;
return AVERROR(ENOMEM);
}
}
if (avctx->pkt_timebase.num && pkt->pts != AV_NOPTS_VALUE)
ctx->pts = av_rescale_q(pkt->pts, avctx->pkt_timebase, AV_TIME_BASE_Q);
if (pkt->size) {
int lines;
const int full_pes_size = pkt->size + 45; /* PES header is 45 bytes */
// We allow unreasonably big packets, even if the standard only allows a max size of 1472
if (full_pes_size < 184 || full_pes_size > 65504 || full_pes_size % 184 != 0)
return AVERROR_INVALIDDATA;
ctx->handler_ret = pkt->size;
if (ff_data_identifier_is_teletext(*pkt->data)) {
if ((lines = slice_to_vbi_lines(ctx, pkt->data + 1, pkt->size - 1)) < 0)
return lines;
ff_dlog(avctx, "ctx=%p buf_size=%d lines=%u pkt_pts=%7.3f\n",
ctx, pkt->size, lines, (double)pkt->pts/90000.0);
if (lines > 0) {
#ifdef DEBUG
int i;
av_log(avctx, AV_LOG_DEBUG, "line numbers:");
for(i = 0; i < lines; i++)
av_log(avctx, AV_LOG_DEBUG, " %d", ctx->sliced[i].line);
av_log(avctx, AV_LOG_DEBUG, "\n");
#endif
vbi_decode(ctx->vbi, ctx->sliced, lines, 0.0);
ctx->lines_processed += lines;
}
}
ctx->pts = AV_NOPTS_VALUE;
ret = ctx->handler_ret;
}
if (ret < 0)
return ret;
// is there a subtitle to pass?
if (ctx->nb_pages) {
int i;
sub->format = ctx->format_id;
sub->start_display_time = 0;
sub->end_display_time = ctx->sub_duration;
sub->num_rects = 0;
sub->pts = ctx->pages->pts;
if (ctx->pages->sub_rect->type != SUBTITLE_NONE) {
sub->rects = av_malloc(sizeof(*sub->rects));
if (sub->rects) {
sub->num_rects = 1;
sub->rects[0] = ctx->pages->sub_rect;
#if FF_API_AVPICTURE
FF_DISABLE_DEPRECATION_WARNINGS
for (j = 0; j < 4; j++) {
sub->rects[0]->pict.data[j] = sub->rects[0]->data[j];
sub->rects[0]->pict.linesize[j] = sub->rects[0]->linesize[j];
}
FF_ENABLE_DEPRECATION_WARNINGS
#endif
} else {
ret = AVERROR(ENOMEM);
}
} else {
av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n");
sub->rects = NULL;
}
if (!sub->rects) // no rect was passed
subtitle_rect_free(&ctx->pages->sub_rect);
for (i = 0; i < ctx->nb_pages - 1; i++)
ctx->pages[i] = ctx->pages[i + 1];
ctx->nb_pages--;
if (ret >= 0)
*data_size = 1;
} else
*data_size = 0;
return ret;
}
static int teletext_init_decoder(AVCodecContext *avctx)
{
TeletextContext *ctx = avctx->priv_data;
unsigned int maj, min, rev;
vbi_version(&maj, &min, &rev);
if (!(maj > 0 || min > 2 || min == 2 && rev >= 26)) {
av_log(avctx, AV_LOG_ERROR, "decoder needs zvbi version >= 0.2.26.\n");
return AVERROR_EXTERNAL;
}
if (ctx->format_id == 0) {
avctx->width = 41 * BITMAP_CHAR_WIDTH;
avctx->height = 25 * BITMAP_CHAR_HEIGHT;
}
ctx->vbi = NULL;
ctx->pts = AV_NOPTS_VALUE;
if (ctx->opacity == -1)
ctx->opacity = ctx->transparent_bg ? 0 : 255;
#ifdef DEBUG
{
char *t;
ctx->ex = vbi_export_new("text", &t);
}
#endif
av_log(avctx, AV_LOG_VERBOSE, "page filter: %s\n", ctx->pgno);
return (ctx->format_id == 1) ? ff_ass_subtitle_header_default(avctx) : 0;
}
static int teletext_close_decoder(AVCodecContext *avctx)
{
TeletextContext *ctx = avctx->priv_data;
ff_dlog(avctx, "lines_total=%u\n", ctx->lines_processed);
while (ctx->nb_pages)
subtitle_rect_free(&ctx->pages[--ctx->nb_pages].sub_rect);
av_freep(&ctx->pages);
vbi_decoder_delete(ctx->vbi);
ctx->vbi = NULL;
ctx->pts = AV_NOPTS_VALUE;
if (!(avctx->flags2 & AV_CODEC_FLAG2_RO_FLUSH_NOOP))
ctx->readorder = 0;
return 0;
}
static void teletext_flush(AVCodecContext *avctx)
{
teletext_close_decoder(avctx);
}
#define OFFSET(x) offsetof(TeletextContext, x)
#define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
{"txt_page", "list of teletext page numbers to decode, * is all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD},
{"txt_chop_top", "discards the top teletext line", OFFSET(chop_top), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
{"txt_format", "format of the subtitles (bitmap or text)", OFFSET(format_id), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD, "txt_format"},
{"bitmap", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, SD, "txt_format"},
{"text", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 0, SD, "txt_format"},
{"txt_left", "x offset of generated bitmaps", OFFSET(x_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
{"txt_top", "y offset of generated bitmaps", OFFSET(y_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
{"txt_chop_spaces", "chops leading and trailing spaces from text", OFFSET(chop_spaces), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
{"txt_duration", "display duration of teletext pages in msecs", OFFSET(sub_duration), AV_OPT_TYPE_INT, {.i64 = 30000}, 0, 86400000, SD},
{"txt_transparent", "force transparent background of the teletext", OFFSET(transparent_bg), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
{"txt_opacity", "set opacity of the transparent background", OFFSET(opacity), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 255, SD},
{ NULL },
};
static const AVClass teletext_class = {
.class_name = "libzvbi_teletextdec",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVCodec ff_libzvbi_teletext_decoder = {
.name = "libzvbi_teletextdec",
.long_name = NULL_IF_CONFIG_SMALL("Libzvbi DVB teletext decoder"),
.type = AVMEDIA_TYPE_SUBTITLE,
.id = AV_CODEC_ID_DVB_TELETEXT,
.priv_data_size = sizeof(TeletextContext),
.init = teletext_init_decoder,
.close = teletext_close_decoder,
.decode = teletext_decode_frame,
.capabilities = AV_CODEC_CAP_DELAY,
.flush = teletext_flush,
.priv_class= &teletext_class,
.wrapper_name = "libzvbi",
};
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