* PGS subtitle decoder
* Copyright (c) 2009 Stephen Backway
*
- * This file is part of FFmpeg.
+ * This file is part of Libav.
*
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
- * @file libavcodec/pgssubdec.c
+ * @file
* PGS subtitle decoder
*/
#include "avcodec.h"
#include "dsputil.h"
-#include "colorspace.h"
#include "bytestream.h"
-
-//#define DEBUG_PACKET_CONTENTS
+#include "libavutil/colorspace.h"
+#include "libavutil/imgutils.h"
#define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
typedef struct PGSSubPresentation {
int x;
int y;
- int video_w;
- int video_h;
int id_number;
+ int object_number;
} PGSSubPresentation;
typedef struct PGSSubPicture {
int h;
uint8_t *rle;
unsigned int rle_buffer_size, rle_data_len;
+ unsigned int rle_remaining_len;
} PGSSubPicture;
typedef struct PGSSubContext {
static av_cold int init_decoder(AVCodecContext *avctx)
{
- avctx->pix_fmt = PIX_FMT_RGB32;
+ avctx->pix_fmt = PIX_FMT_PAL8;
return 0;
}
}
/**
- * Decodes the RLE data.
+ * Decode the RLE data.
*
* The subtitle is stored as an Run Length Encoded image.
*
}
}
- dprintf(avctx, "Pixel Count = %d, Area = %d\n", pixel_count, sub->rects[0]->w * sub->rects[0]->h);
+ if (pixel_count < sub->rects[0]->w * sub->rects[0]->h) {
+ av_log(avctx, AV_LOG_ERROR, "Insufficient RLE data for subtitle\n");
+ return -1;
+ }
+
+ av_dlog(avctx, "Pixel Count = %d, Area = %d\n", pixel_count, sub->rects[0]->w * sub->rects[0]->h);
return 0;
}
/**
- * Parses the picture segment packet.
+ * Parse the picture segment packet.
*
* The picture segment contains details on the sequence id,
* width, height and Run Length Encoded (RLE) bitmap data.
uint8_t sequence_desc;
unsigned int rle_bitmap_len, width, height;
+ if (buf_size <= 4)
+ return -1;
+ buf_size -= 4;
+
/* skip 3 unknown bytes: Object ID (2 bytes), Version Number */
buf += 3;
sequence_desc = bytestream_get_byte(&buf);
if (!(sequence_desc & 0x80)) {
- av_log(avctx, AV_LOG_ERROR, "Decoder does not support object data over multiple packets.\n");
- return -1;
- }
+ /* Additional RLE data */
+ if (buf_size > ctx->picture.rle_remaining_len)
+ return -1;
- /* Decode rle bitmap length */
- rle_bitmap_len = bytestream_get_be24(&buf);
+ memcpy(ctx->picture.rle + ctx->picture.rle_data_len, buf, buf_size);
+ ctx->picture.rle_data_len += buf_size;
+ ctx->picture.rle_remaining_len -= buf_size;
- /* Check to ensure we have enough data for rle_bitmap_length if just a single packet */
- if (rle_bitmap_len > buf_size - 7) {
- av_log(avctx, AV_LOG_ERROR, "Not enough RLE data for specified length of %d.\n", rle_bitmap_len);
- return -1;
+ return 0;
}
- ctx->picture.rle_data_len = rle_bitmap_len;
+ if (buf_size <= 7)
+ return -1;
+ buf_size -= 7;
+
+ /* Decode rle bitmap length, stored size includes width/height data */
+ rle_bitmap_len = bytestream_get_be24(&buf) - 2*2;
/* Get bitmap dimensions from data */
width = bytestream_get_be16(&buf);
height = bytestream_get_be16(&buf);
/* Make sure the bitmap is not too large */
- if (ctx->presentation.video_w < width || ctx->presentation.video_h < height) {
- av_log(avctx, AV_LOG_ERROR, "Bitmap dimensions larger then video.\n");
+ if (avctx->width < width || avctx->height < height) {
+ av_log(avctx, AV_LOG_ERROR, "Bitmap dimensions larger than video.\n");
return -1;
}
if (!ctx->picture.rle)
return -1;
- memcpy(ctx->picture.rle, buf, rle_bitmap_len);
+ memcpy(ctx->picture.rle, buf, buf_size);
+ ctx->picture.rle_data_len = buf_size;
+ ctx->picture.rle_remaining_len = rle_bitmap_len - buf_size;
return 0;
}
/**
- * Parses the palette segment packet.
+ * Parse the palette segment packet.
*
* The palette segment contains details of the palette,
* a maximum of 256 colors can be defined.
while (buf < buf_end) {
color_id = bytestream_get_byte(&buf);
y = bytestream_get_byte(&buf);
- cb = bytestream_get_byte(&buf);
cr = bytestream_get_byte(&buf);
+ cb = bytestream_get_byte(&buf);
alpha = bytestream_get_byte(&buf);
YUV_TO_RGB1(cb, cr);
YUV_TO_RGB2(r, g, b, y);
- dprintf(avctx, "Color %d := (%d,%d,%d,%d)\n", color_id, r, g, b, alpha);
+ av_dlog(avctx, "Color %d := (%d,%d,%d,%d)\n", color_id, r, g, b, alpha);
/* Store color in palette */
ctx->clut[color_id] = RGBA(r,g,b,alpha);
}
/**
- * Parses the presentation segment packet.
+ * Parse the presentation segment packet.
*
* The presentation segment contains details on the video
* width, video height, x & y subtitle position.
* @param buf_size size of packet to process
* @todo TODO: Implement cropping
* @todo TODO: Implement forcing of subtitles
- * @todo TODO: Blanking of subtitle
*/
static void parse_presentation_segment(AVCodecContext *avctx,
const uint8_t *buf, int buf_size)
PGSSubContext *ctx = avctx->priv_data;
int x, y;
- uint8_t block;
- ctx->presentation.video_w = bytestream_get_be16(&buf);
- ctx->presentation.video_h = bytestream_get_be16(&buf);
+ int w = bytestream_get_be16(&buf);
+ int h = bytestream_get_be16(&buf);
- dprintf(avctx, "Video Dimensions %dx%d\n",
- ctx->presentation.video_w, ctx->presentation.video_h);
+ av_dlog(avctx, "Video Dimensions %dx%d\n",
+ w, h);
+ if (av_image_check_size(w, h, 0, avctx) >= 0)
+ avcodec_set_dimensions(avctx, w, h);
/* Skip 1 bytes of unknown, frame rate? */
buf++;
ctx->presentation.id_number = bytestream_get_be16(&buf);
- /* Next byte is the state. */
- block = bytestream_get_byte(&buf);;
- if (block == 0x80) {
- /*
- * Skip 7 bytes of unknown:
- * palette_update_flag (0x80),
- * palette_id_to_use,
- * Object Number (if > 0 determines if more data to process),
- * object_id_ref (2 bytes),
- * window_id_ref,
- * composition_flag (0x80 - object cropped, 0x40 - object forced)
- */
- buf += 7;
-
- x = bytestream_get_be16(&buf);
- y = bytestream_get_be16(&buf);
-
- /* TODO If cropping, cropping_x, cropping_y, cropping_width, cropping_height (all 2 bytes).*/
-
- dprintf(avctx, "Subtitle Placement x=%d, y=%d\n", x, y);
-
- if (x > ctx->presentation.video_w || y > ctx->presentation.video_h) {
- av_log(avctx, AV_LOG_ERROR, "Subtitle out of video bounds. x = %d, y = %d, video width = %d, video height = %d.\n",
- x, y, ctx->presentation.video_w, ctx->presentation.video_h);
- x = 0; y = 0;
- }
+ /*
+ * Skip 3 bytes of unknown:
+ * state
+ * palette_update_flag (0x80),
+ * palette_id_to_use,
+ */
+ buf += 3;
+
+ ctx->presentation.object_number = bytestream_get_byte(&buf);
+ if (!ctx->presentation.object_number)
+ return;
+
+ /*
+ * Skip 4 bytes of unknown:
+ * object_id_ref (2 bytes),
+ * window_id_ref,
+ * composition_flag (0x80 - object cropped, 0x40 - object forced)
+ */
+ buf += 4;
- /* Fill in dimensions */
- ctx->presentation.x = x;
- ctx->presentation.y = y;
- } else if (block == 0x00) {
- /* TODO: Blank context as subtitle should not be displayed.
- * If the subtitle is blanked now the subtitle is not
- * on screen long enough to read, due to a delay in
- * initial display timing.
- */
+ x = bytestream_get_be16(&buf);
+ y = bytestream_get_be16(&buf);
+
+ /* TODO If cropping, cropping_x, cropping_y, cropping_width, cropping_height (all 2 bytes).*/
+
+ av_dlog(avctx, "Subtitle Placement x=%d, y=%d\n", x, y);
+
+ if (x > avctx->width || y > avctx->height) {
+ av_log(avctx, AV_LOG_ERROR, "Subtitle out of video bounds. x = %d, y = %d, video width = %d, video height = %d.\n",
+ x, y, avctx->width, avctx->height);
+ x = 0; y = 0;
}
+
+ /* Fill in dimensions */
+ ctx->presentation.x = x;
+ ctx->presentation.y = y;
}
/**
- * Parses the display segment packet.
+ * Parse the display segment packet.
*
* The display segment controls the updating of the display.
*
*/
memset(sub, 0, sizeof(*sub));
+ // Blank if last object_number was 0.
+ // Note that this may be wrong for more complex subtitles.
+ if (!ctx->presentation.object_number)
+ return 1;
sub->start_display_time = 0;
sub->end_display_time = 20000;
sub->format = 0;
/* Process bitmap */
sub->rects[0]->pict.linesize[0] = ctx->picture.w;
- if (ctx->picture.rle)
+ if (ctx->picture.rle) {
+ if (ctx->picture.rle_remaining_len)
+ av_log(avctx, AV_LOG_ERROR, "RLE data length %u is %u bytes shorter than expected\n",
+ ctx->picture.rle_data_len, ctx->picture.rle_remaining_len);
if(decode_rle(avctx, sub, ctx->picture.rle, ctx->picture.rle_data_len) < 0)
return 0;
-
+ }
/* Allocate memory for colors */
sub->rects[0]->nb_colors = 256;
- sub->rects[0]->pict.data[1] = av_malloc(sub->rects[0]->nb_colors * sizeof(uint32_t));
+ sub->rects[0]->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
memcpy(sub->rects[0]->pict.data[1], ctx->clut, sub->rects[0]->nb_colors * sizeof(uint32_t));
const uint8_t *buf_end;
uint8_t segment_type;
int segment_length;
-
-#ifdef DEBUG_PACKET_CONTENTS
int i;
- av_log(avctx, AV_LOG_INFO, "PGS sub packet:\n");
+ av_dlog(avctx, "PGS sub packet:\n");
for (i = 0; i < buf_size; i++) {
- av_log(avctx, AV_LOG_INFO, "%02x ", buf[i]);
+ av_dlog(avctx, "%02x ", buf[i]);
if (i % 16 == 15)
- av_log(avctx, AV_LOG_INFO, "\n");
+ av_dlog(avctx, "\n");
}
if (i & 15)
- av_log(avctx, AV_LOG_INFO, "\n");
-#endif
+ av_dlog(avctx, "\n");
*data_size = 0;
segment_type = bytestream_get_byte(&buf);
segment_length = bytestream_get_be16(&buf);
- dprintf(avctx, "Segment Length %d, Segment Type %x\n", segment_length, segment_type);
+ av_dlog(avctx, "Segment Length %d, Segment Type %x\n", segment_length, segment_type);
if (segment_type != DISPLAY_SEGMENT && segment_length > buf_end - buf)
break;
return buf_size;
}
-AVCodec pgssub_decoder = {
- "pgssub",
- CODEC_TYPE_SUBTITLE,
- CODEC_ID_HDMV_PGS_SUBTITLE,
- sizeof(PGSSubContext),
- init_decoder,
- NULL,
- close_decoder,
- decode,
+AVCodec ff_pgssub_decoder = {
+ .name = "pgssub",
+ .type = AVMEDIA_TYPE_SUBTITLE,
+ .id = CODEC_ID_HDMV_PGS_SUBTITLE,
+ .priv_data_size = sizeof(PGSSubContext),
+ .init = init_decoder,
+ .close = close_decoder,
+ .decode = decode,
.long_name = NULL_IF_CONFIG_SMALL("HDMV Presentation Graphic Stream subtitles"),
};