forked from KolibriOS/kolibrios
550 lines
17 KiB
C
550 lines
17 KiB
C
/*
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* PGS subtitle decoder
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* Copyright (c) 2009 Stephen Backway
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* PGS subtitle decoder
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*/
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#include "avcodec.h"
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#include "dsputil.h"
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#include "bytestream.h"
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#include "libavutil/colorspace.h"
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#include "libavutil/imgutils.h"
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#include "libavutil/opt.h"
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#define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
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enum SegmentType {
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PALETTE_SEGMENT = 0x14,
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PICTURE_SEGMENT = 0x15,
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PRESENTATION_SEGMENT = 0x16,
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WINDOW_SEGMENT = 0x17,
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DISPLAY_SEGMENT = 0x80,
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};
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typedef struct PGSSubPictureReference {
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int x;
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int y;
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int picture_id;
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int composition;
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} PGSSubPictureReference;
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typedef struct PGSSubPresentation {
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int id_number;
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int object_count;
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PGSSubPictureReference *objects;
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int64_t pts;
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} PGSSubPresentation;
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typedef struct PGSSubPicture {
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int w;
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int h;
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uint8_t *rle;
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unsigned int rle_buffer_size, rle_data_len;
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unsigned int rle_remaining_len;
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} PGSSubPicture;
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typedef struct PGSSubContext {
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AVClass *class;
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PGSSubPresentation presentation;
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uint32_t clut[256];
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PGSSubPicture pictures[UINT16_MAX];
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int forced_subs_only;
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} PGSSubContext;
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static av_cold int init_decoder(AVCodecContext *avctx)
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{
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avctx->pix_fmt = AV_PIX_FMT_PAL8;
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return 0;
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}
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static av_cold int close_decoder(AVCodecContext *avctx)
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{
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uint16_t picture;
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PGSSubContext *ctx = avctx->priv_data;
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av_freep(&ctx->presentation.objects);
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ctx->presentation.object_count = 0;
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for (picture = 0; picture < UINT16_MAX; ++picture) {
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av_freep(&ctx->pictures[picture].rle);
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ctx->pictures[picture].rle_buffer_size = 0;
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}
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return 0;
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}
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/**
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* Decode the RLE data.
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*
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* The subtitle is stored as a Run Length Encoded image.
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*
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* @param avctx contains the current codec context
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* @param sub pointer to the processed subtitle data
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* @param buf pointer to the RLE data to process
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* @param buf_size size of the RLE data to process
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*/
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static int decode_rle(AVCodecContext *avctx, AVSubtitle *sub, int rect,
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const uint8_t *buf, unsigned int buf_size)
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{
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const uint8_t *rle_bitmap_end;
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int pixel_count, line_count;
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rle_bitmap_end = buf + buf_size;
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sub->rects[rect]->pict.data[0] = av_malloc(sub->rects[rect]->w * sub->rects[rect]->h);
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if (!sub->rects[rect]->pict.data[0])
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return -1;
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pixel_count = 0;
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line_count = 0;
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while (buf < rle_bitmap_end && line_count < sub->rects[rect]->h) {
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uint8_t flags, color;
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int run;
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color = bytestream_get_byte(&buf);
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run = 1;
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if (color == 0x00) {
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flags = bytestream_get_byte(&buf);
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run = flags & 0x3f;
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if (flags & 0x40)
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run = (run << 8) + bytestream_get_byte(&buf);
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color = flags & 0x80 ? bytestream_get_byte(&buf) : 0;
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}
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if (run > 0 && pixel_count + run <= sub->rects[rect]->w * sub->rects[rect]->h) {
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memset(sub->rects[rect]->pict.data[0] + pixel_count, color, run);
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pixel_count += run;
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} else if (!run) {
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/*
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* New Line. Check if correct pixels decoded, if not display warning
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* and adjust bitmap pointer to correct new line position.
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*/
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if (pixel_count % sub->rects[rect]->w > 0)
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av_log(avctx, AV_LOG_ERROR, "Decoded %d pixels, when line should be %d pixels\n",
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pixel_count % sub->rects[rect]->w, sub->rects[rect]->w);
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line_count++;
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}
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}
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if (pixel_count < sub->rects[rect]->w * sub->rects[rect]->h) {
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av_log(avctx, AV_LOG_ERROR, "Insufficient RLE data for subtitle\n");
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return -1;
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}
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av_dlog(avctx, "Pixel Count = %d, Area = %d\n", pixel_count, sub->rects[rect]->w * sub->rects[rect]->h);
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return 0;
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}
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/**
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* Parse the picture segment packet.
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*
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* The picture segment contains details on the sequence id,
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* width, height and Run Length Encoded (RLE) bitmap data.
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*
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* @param avctx contains the current codec context
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* @param buf pointer to the packet to process
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* @param buf_size size of packet to process
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* @todo TODO: Enable support for RLE data over multiple packets
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*/
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static int parse_picture_segment(AVCodecContext *avctx,
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const uint8_t *buf, int buf_size)
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{
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PGSSubContext *ctx = avctx->priv_data;
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uint8_t sequence_desc;
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unsigned int rle_bitmap_len, width, height;
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uint16_t picture_id;
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if (buf_size <= 4)
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return -1;
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buf_size -= 4;
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picture_id = bytestream_get_be16(&buf);
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/* skip 1 unknown byte: Version Number */
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buf++;
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/* Read the Sequence Description to determine if start of RLE data or appended to previous RLE */
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sequence_desc = bytestream_get_byte(&buf);
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if (!(sequence_desc & 0x80)) {
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/* Additional RLE data */
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if (buf_size > ctx->pictures[picture_id].rle_remaining_len)
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return -1;
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memcpy(ctx->pictures[picture_id].rle + ctx->pictures[picture_id].rle_data_len, buf, buf_size);
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ctx->pictures[picture_id].rle_data_len += buf_size;
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ctx->pictures[picture_id].rle_remaining_len -= buf_size;
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return 0;
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}
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if (buf_size <= 7)
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return -1;
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buf_size -= 7;
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/* Decode rle bitmap length, stored size includes width/height data */
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rle_bitmap_len = bytestream_get_be24(&buf) - 2*2;
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/* Get bitmap dimensions from data */
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width = bytestream_get_be16(&buf);
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height = bytestream_get_be16(&buf);
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/* Make sure the bitmap is not too large */
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if (avctx->width < width || avctx->height < height) {
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av_log(avctx, AV_LOG_ERROR, "Bitmap dimensions larger than video.\n");
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return -1;
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}
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if (buf_size > rle_bitmap_len) {
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av_log(avctx, AV_LOG_ERROR, "too much RLE data\n");
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return AVERROR_INVALIDDATA;
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}
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ctx->pictures[picture_id].w = width;
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ctx->pictures[picture_id].h = height;
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av_fast_malloc(&ctx->pictures[picture_id].rle, &ctx->pictures[picture_id].rle_buffer_size, rle_bitmap_len);
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if (!ctx->pictures[picture_id].rle)
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return -1;
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memcpy(ctx->pictures[picture_id].rle, buf, buf_size);
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ctx->pictures[picture_id].rle_data_len = buf_size;
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ctx->pictures[picture_id].rle_remaining_len = rle_bitmap_len - buf_size;
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return 0;
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}
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/**
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* Parse the palette segment packet.
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*
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* The palette segment contains details of the palette,
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* a maximum of 256 colors can be defined.
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*
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* @param avctx contains the current codec context
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* @param buf pointer to the packet to process
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* @param buf_size size of packet to process
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*/
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static void parse_palette_segment(AVCodecContext *avctx,
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const uint8_t *buf, int buf_size)
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{
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PGSSubContext *ctx = avctx->priv_data;
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const uint8_t *buf_end = buf + buf_size;
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const uint8_t *cm = ff_cropTbl + MAX_NEG_CROP;
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int color_id;
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int y, cb, cr, alpha;
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int r, g, b, r_add, g_add, b_add;
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/* Skip two null bytes */
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buf += 2;
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while (buf < buf_end) {
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color_id = bytestream_get_byte(&buf);
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y = bytestream_get_byte(&buf);
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cr = bytestream_get_byte(&buf);
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cb = bytestream_get_byte(&buf);
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alpha = bytestream_get_byte(&buf);
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YUV_TO_RGB1(cb, cr);
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YUV_TO_RGB2(r, g, b, y);
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av_dlog(avctx, "Color %d := (%d,%d,%d,%d)\n", color_id, r, g, b, alpha);
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/* Store color in palette */
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ctx->clut[color_id] = RGBA(r,g,b,alpha);
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}
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}
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/**
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* Parse the presentation segment packet.
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*
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* The presentation segment contains details on the video
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* width, video height, x & y subtitle position.
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*
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* @param avctx contains the current codec context
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* @param buf pointer to the packet to process
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* @param buf_size size of packet to process
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* @todo TODO: Implement cropping
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*/
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static void parse_presentation_segment(AVCodecContext *avctx,
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const uint8_t *buf, int buf_size,
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int64_t pts)
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{
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PGSSubContext *ctx = avctx->priv_data;
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int w = bytestream_get_be16(&buf);
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int h = bytestream_get_be16(&buf);
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uint16_t object_index;
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ctx->presentation.pts = pts;
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av_dlog(avctx, "Video Dimensions %dx%d\n",
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w, h);
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if (av_image_check_size(w, h, 0, avctx) >= 0)
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avcodec_set_dimensions(avctx, w, h);
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/* Skip 1 bytes of unknown, frame rate? */
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buf++;
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ctx->presentation.id_number = bytestream_get_be16(&buf);
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/*
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* Skip 3 bytes of unknown:
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* state
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* palette_update_flag (0x80),
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* palette_id_to_use,
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*/
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buf += 3;
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ctx->presentation.object_count = bytestream_get_byte(&buf);
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if (!ctx->presentation.object_count)
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return;
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/* Verify that enough bytes are remaining for all of the objects. */
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buf_size -= 11;
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if (buf_size < ctx->presentation.object_count * 8) {
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ctx->presentation.object_count = 0;
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return;
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}
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av_freep(&ctx->presentation.objects);
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ctx->presentation.objects = av_malloc(sizeof(PGSSubPictureReference) * ctx->presentation.object_count);
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if (!ctx->presentation.objects) {
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ctx->presentation.object_count = 0;
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return;
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}
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for (object_index = 0; object_index < ctx->presentation.object_count; ++object_index) {
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PGSSubPictureReference *reference = &ctx->presentation.objects[object_index];
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reference->picture_id = bytestream_get_be16(&buf);
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/* Skip window_id_ref */
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buf++;
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/* composition_flag (0x80 - object cropped, 0x40 - object forced) */
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reference->composition = bytestream_get_byte(&buf);
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reference->x = bytestream_get_be16(&buf);
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reference->y = bytestream_get_be16(&buf);
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/* TODO If cropping, cropping_x, cropping_y, cropping_width, cropping_height (all 2 bytes).*/
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av_dlog(avctx, "Subtitle Placement ID=%d, x=%d, y=%d\n", reference->picture_id, reference->x, reference->y);
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if (reference->x > avctx->width || reference->y > avctx->height) {
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av_log(avctx, AV_LOG_ERROR, "Subtitle out of video bounds. x = %d, y = %d, video width = %d, video height = %d.\n",
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reference->x, reference->y, avctx->width, avctx->height);
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reference->x = 0;
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reference->y = 0;
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}
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}
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}
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/**
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* Parse the display segment packet.
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*
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* The display segment controls the updating of the display.
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*
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* @param avctx contains the current codec context
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* @param data pointer to the data pertaining the subtitle to display
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* @param buf pointer to the packet to process
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* @param buf_size size of packet to process
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* @todo TODO: Fix start time, relies on correct PTS, currently too late
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*
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* @todo TODO: Fix end time, normally cleared by a second display
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* @todo segment, which is currently ignored as it clears
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* @todo the subtitle too early.
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*/
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static int display_end_segment(AVCodecContext *avctx, void *data,
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const uint8_t *buf, int buf_size)
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{
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AVSubtitle *sub = data;
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PGSSubContext *ctx = avctx->priv_data;
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int64_t pts;
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uint16_t rect;
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/*
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* The end display time is a timeout value and is only reached
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* if the next subtitle is later than timeout or subtitle has
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* not been cleared by a subsequent empty display command.
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*/
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pts = ctx->presentation.pts != AV_NOPTS_VALUE ? ctx->presentation.pts : sub->pts;
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memset(sub, 0, sizeof(*sub));
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sub->pts = pts;
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ctx->presentation.pts = AV_NOPTS_VALUE;
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// Blank if last object_count was 0.
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if (!ctx->presentation.object_count)
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return 1;
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sub->start_display_time = 0;
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sub->end_display_time = 20000;
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sub->format = 0;
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sub->num_rects = ctx->presentation.object_count;
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sub->rects = av_mallocz(sizeof(*sub->rects) * sub->num_rects);
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for (rect = 0; rect < sub->num_rects; ++rect) {
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uint16_t picture_id = ctx->presentation.objects[rect].picture_id;
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sub->rects[rect] = av_mallocz(sizeof(*sub->rects[rect]));
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sub->rects[rect]->x = ctx->presentation.objects[rect].x;
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sub->rects[rect]->y = ctx->presentation.objects[rect].y;
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sub->rects[rect]->w = ctx->pictures[picture_id].w;
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sub->rects[rect]->h = ctx->pictures[picture_id].h;
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sub->rects[rect]->type = SUBTITLE_BITMAP;
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/* Process bitmap */
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sub->rects[rect]->pict.linesize[0] = ctx->pictures[picture_id].w;
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if (ctx->pictures[picture_id].rle) {
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if (ctx->pictures[picture_id].rle_remaining_len)
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av_log(avctx, AV_LOG_ERROR, "RLE data length %u is %u bytes shorter than expected\n",
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ctx->pictures[picture_id].rle_data_len, ctx->pictures[picture_id].rle_remaining_len);
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if (decode_rle(avctx, sub, rect, ctx->pictures[picture_id].rle, ctx->pictures[picture_id].rle_data_len) < 0)
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return 0;
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}
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/* Allocate memory for colors */
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sub->rects[rect]->nb_colors = 256;
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sub->rects[rect]->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
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/* Copy the forced flag */
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sub->rects[rect]->flags = (ctx->presentation.objects[rect].composition & 0x40) != 0 ? AV_SUBTITLE_FLAG_FORCED : 0;
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if (!ctx->forced_subs_only || ctx->presentation.objects[rect].composition & 0x40)
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memcpy(sub->rects[rect]->pict.data[1], ctx->clut, sub->rects[rect]->nb_colors * sizeof(uint32_t));
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}
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return 1;
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}
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static int decode(AVCodecContext *avctx, void *data, int *data_size,
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AVPacket *avpkt)
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{
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const uint8_t *buf = avpkt->data;
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int buf_size = avpkt->size;
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AVSubtitle *sub = data;
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const uint8_t *buf_end;
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uint8_t segment_type;
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int segment_length;
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int i;
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av_dlog(avctx, "PGS sub packet:\n");
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for (i = 0; i < buf_size; i++) {
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av_dlog(avctx, "%02x ", buf[i]);
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if (i % 16 == 15)
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av_dlog(avctx, "\n");
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}
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if (i & 15)
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av_dlog(avctx, "\n");
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*data_size = 0;
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/* Ensure that we have received at a least a segment code and segment length */
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if (buf_size < 3)
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return -1;
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buf_end = buf + buf_size;
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/* Step through buffer to identify segments */
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while (buf < buf_end) {
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segment_type = bytestream_get_byte(&buf);
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segment_length = bytestream_get_be16(&buf);
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av_dlog(avctx, "Segment Length %d, Segment Type %x\n", segment_length, segment_type);
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if (segment_type != DISPLAY_SEGMENT && segment_length > buf_end - buf)
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break;
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switch (segment_type) {
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case PALETTE_SEGMENT:
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parse_palette_segment(avctx, buf, segment_length);
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break;
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case PICTURE_SEGMENT:
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parse_picture_segment(avctx, buf, segment_length);
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break;
|
|
case PRESENTATION_SEGMENT:
|
|
parse_presentation_segment(avctx, buf, segment_length, sub->pts);
|
|
break;
|
|
case WINDOW_SEGMENT:
|
|
/*
|
|
* Window Segment Structure (No new information provided):
|
|
* 2 bytes: Unknown,
|
|
* 2 bytes: X position of subtitle,
|
|
* 2 bytes: Y position of subtitle,
|
|
* 2 bytes: Width of subtitle,
|
|
* 2 bytes: Height of subtitle.
|
|
*/
|
|
break;
|
|
case DISPLAY_SEGMENT:
|
|
*data_size = display_end_segment(avctx, data, buf, segment_length);
|
|
break;
|
|
default:
|
|
av_log(avctx, AV_LOG_ERROR, "Unknown subtitle segment type 0x%x, length %d\n",
|
|
segment_type, segment_length);
|
|
break;
|
|
}
|
|
|
|
buf += segment_length;
|
|
}
|
|
|
|
return buf_size;
|
|
}
|
|
|
|
#define OFFSET(x) offsetof(PGSSubContext, x)
|
|
#define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
|
|
static const AVOption options[] = {
|
|
{"forced_subs_only", "Only show forced subtitles", OFFSET(forced_subs_only), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
|
|
{ NULL },
|
|
};
|
|
|
|
static const AVClass pgsdec_class = {
|
|
.class_name = "PGS subtitle decoder",
|
|
.item_name = av_default_item_name,
|
|
.option = options,
|
|
.version = LIBAVUTIL_VERSION_INT,
|
|
};
|
|
|
|
AVCodec ff_pgssub_decoder = {
|
|
.name = "pgssub",
|
|
.long_name = NULL_IF_CONFIG_SMALL("HDMV Presentation Graphic Stream subtitles"),
|
|
.type = AVMEDIA_TYPE_SUBTITLE,
|
|
.id = AV_CODEC_ID_HDMV_PGS_SUBTITLE,
|
|
.priv_data_size = sizeof(PGSSubContext),
|
|
.init = init_decoder,
|
|
.close = close_decoder,
|
|
.decode = decode,
|
|
.priv_class = &pgsdec_class,
|
|
};
|