mirror of https://github.com/FFmpeg/FFmpeg.git
Patch by Stephen Backway, stev391 A exemail D com D au Originally committed as revision 19699 to svn://svn.ffmpeg.org/ffmpeg/trunkrelease/0.6
Stephen Backway
16 years ago
committed by
Carl Eugen Hoyos
parent
49056037a8
commit
c58b82a29b
7 changed files with 473 additions and 1 deletions
@ -0,0 +1,466 @@ |
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/*
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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 libavcodec/pgssubdec.c |
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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 "colorspace.h" |
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#include "bytestream.h" |
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//#define DEBUG_PACKET_CONTENTS
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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 PGSSubPresentation { |
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int x; |
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int y; |
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int video_w; |
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int video_h; |
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int id_number; |
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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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} PGSSubPicture; |
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typedef struct PGSSubContext { |
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PGSSubPresentation presentation; |
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uint32_t clut[256]; |
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PGSSubPicture picture; |
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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 = PIX_FMT_RGB32; |
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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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PGSSubContext *ctx = avctx->priv_data; |
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av_freep(&ctx->picture.rle); |
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ctx->picture.rle_buffer_size = 0; |
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return 0; |
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} |
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/**
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* Decodes the RLE data. |
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* |
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* The subtitle is stored as an 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, |
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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[0]->pict.data[0] = av_malloc(sub->rects[0]->w * sub->rects[0]->h); |
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if (!sub->rects[0]->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[0]->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[0]->w * sub->rects[0]->h) { |
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memset(sub->rects[0]->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[0]->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[0]->w, sub->rects[0]->w); |
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line_count++; |
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} |
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} |
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dprintf(avctx, "Pixel Count = %d, Area = %d\n", pixel_count, sub->rects[0]->w * sub->rects[0]->h); |
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return 0; |
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} |
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/**
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* Parses 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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/* skip 3 unknown bytes: Object ID (2 bytes), Version Number */ |
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buf += 3; |
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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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av_log(avctx, AV_LOG_ERROR, "Decoder does not support object data over multiple packets.\n"); |
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return -1; |
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} |
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/* Decode rle bitmap length */ |
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rle_bitmap_len = bytestream_get_be24(&buf); |
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/* Check to ensure we have enough data for rle_bitmap_length if just a single packet */ |
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if (rle_bitmap_len > buf_size - 7) { |
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av_log(avctx, AV_LOG_ERROR, "Not enough RLE data for specified length of %d.\n", rle_bitmap_len); |
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return -1; |
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} |
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ctx->picture.rle_data_len = rle_bitmap_len; |
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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 (ctx->presentation.video_w < width || ctx->presentation.video_h < height) { |
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av_log(avctx, AV_LOG_ERROR, "Bitmap dimensions larger then video.\n"); |
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return -1; |
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} |
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ctx->picture.w = width; |
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ctx->picture.h = height; |
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av_fast_malloc(&ctx->picture.rle, &ctx->picture.rle_buffer_size, rle_bitmap_len); |
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if (!ctx->picture.rle) |
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return -1; |
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memcpy(ctx->picture.rle, buf, rle_bitmap_len); |
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return 0; |
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} |
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/**
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* Parses 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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cb = bytestream_get_byte(&buf); |
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cr = 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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dprintf(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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* Parses 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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* @todo TODO: Implement forcing of subtitles |
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* @todo TODO: Blanking of subtitle |
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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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{ |
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PGSSubContext *ctx = avctx->priv_data; |
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int x, y; |
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uint8_t block; |
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ctx->presentation.video_w = bytestream_get_be16(&buf); |
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ctx->presentation.video_h = bytestream_get_be16(&buf); |
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dprintf(avctx, "Video Dimensions %dx%d\n", |
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ctx->presentation.video_w, ctx->presentation.video_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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/* Next byte is the state. */ |
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block = bytestream_get_byte(&buf);; |
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if (block == 0x80) { |
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/*
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* Skip 7 bytes of unknown: |
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* palette_update_flag (0x80), |
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* palette_id_to_use, |
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* Object Number (if > 0 determines if more data to process), |
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* object_id_ref (2 bytes), |
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* window_id_ref, |
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* composition_flag (0x80 - object cropped, 0x40 - object forced) |
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*/ |
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buf += 7; |
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x = bytestream_get_be16(&buf); |
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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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dprintf(avctx, "Subtitle Placement x=%d, y=%d\n", x, y); |
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if (x > ctx->presentation.video_w || y > ctx->presentation.video_h) { |
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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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x, y, ctx->presentation.video_w, ctx->presentation.video_h); |
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x = 0; y = 0; |
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} |
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/* Fill in dimensions */ |
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ctx->presentation.x = x; |
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ctx->presentation.y = y; |
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} else if (block == 0x00) { |
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/* TODO: Blank context as subtitle should not be displayed.
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* If the subtitle is blanked now the subtitle is not |
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* on screen long enough to read, due to a delay in |
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* initial display timing. |
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*/ |
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} |
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} |
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/**
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* Parses 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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/*
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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 then 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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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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if (!sub->rects) { |
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sub->rects = av_mallocz(sizeof(*sub->rects)); |
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sub->rects[0] = av_mallocz(sizeof(*sub->rects[0])); |
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sub->num_rects = 1; |
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} |
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sub->rects[0]->x = ctx->presentation.x; |
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sub->rects[0]->y = ctx->presentation.y; |
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sub->rects[0]->w = ctx->picture.w; |
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sub->rects[0]->h = ctx->picture.h; |
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sub->rects[0]->type = SUBTITLE_BITMAP; |
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/* Process bitmap */ |
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sub->rects[0]->pict.linesize[0] = ctx->picture.w; |
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if (ctx->picture.rle) |
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if(decode_rle(avctx, sub, ctx->picture.rle, ctx->picture.rle_data_len) < 0) |
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return 0; |
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/* Allocate memory for colors */ |
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sub->rects[0]->nb_colors = 256; |
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sub->rects[0]->pict.data[1] = av_malloc(sub->rects[0]->nb_colors * sizeof(uint32_t)); |
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memcpy(sub->rects[0]->pict.data[1], ctx->clut, sub->rects[0]->nb_colors * sizeof(uint32_t)); |
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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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const uint8_t *buf_end; |
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uint8_t segment_type; |
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int segment_length; |
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#ifdef DEBUG_PACKET_CONTENTS |
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int i; |
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av_log(avctx, AV_LOG_INFO, "PGS sub packet:\n"); |
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for (i = 0; i < buf_size; i++) { |
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av_log(avctx, AV_LOG_INFO, "%02x ", buf[i]); |
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if (i % 16 == 15) |
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av_log(avctx, AV_LOG_INFO, "\n"); |
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} |
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if (i & 15) |
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av_log(avctx, AV_LOG_INFO, "\n"); |
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#endif |
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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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dprintf(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; |
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case PRESENTATION_SEGMENT: |
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parse_presentation_segment(avctx, buf, segment_length); |
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break; |
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case WINDOW_SEGMENT: |
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/*
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* Window Segment Structure (No new information provided): |
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* 2 bytes: Unkown, |
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* 2 bytes: X position of subtitle, |
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* 2 bytes: Y position of subtitle, |
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* 2 bytes: Width of subtitle, |
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* 2 bytes: Height of subtitle. |
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*/ |
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break; |
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case DISPLAY_SEGMENT: |
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*data_size = display_end_segment(avctx, data, buf, segment_length); |
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break; |
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default: |
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av_log(avctx, AV_LOG_ERROR, "Unknown subtitle segment type 0x%x, length %d\n", |
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segment_type, segment_length); |
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break; |
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} |
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buf += segment_length; |
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} |
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return buf_size; |
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} |
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AVCodec pgssub_decoder = { |
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"pgssub", |
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CODEC_TYPE_SUBTITLE, |
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CODEC_ID_HDMV_PGS_SUBTITLE, |
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sizeof(PGSSubContext), |
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init_decoder, |
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NULL, |
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close_decoder, |
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decode, |
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.long_name = NULL_IF_CONFIG_SMALL("HDMV Presentation Graphic Stream subtitles"), |
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}; |
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