0,0 → 1,549 |
/* |
* PGS subtitle decoder |
* Copyright (c) 2009 Stephen Backway |
* |
* This file is part of FFmpeg. |
* |
* FFmpeg is free software; you can redistribute it and/or |
* modify it under the terms of the GNU Lesser General Public |
* License as published by the Free Software Foundation; either |
* version 2.1 of the License, or (at your option) any later version. |
* |
* FFmpeg is distributed in the hope that it will be useful, |
* but WITHOUT ANY WARRANTY; without even the implied warranty of |
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
* Lesser General Public License for more details. |
* |
* You should have received a copy of the GNU Lesser General Public |
* License along with FFmpeg; if not, write to the Free Software |
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
*/ |
|
/** |
* @file |
* PGS subtitle decoder |
*/ |
|
#include "avcodec.h" |
#include "dsputil.h" |
#include "bytestream.h" |
#include "libavutil/colorspace.h" |
#include "libavutil/imgutils.h" |
#include "libavutil/opt.h" |
|
#define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b)) |
|
enum SegmentType { |
PALETTE_SEGMENT = 0x14, |
PICTURE_SEGMENT = 0x15, |
PRESENTATION_SEGMENT = 0x16, |
WINDOW_SEGMENT = 0x17, |
DISPLAY_SEGMENT = 0x80, |
}; |
|
typedef struct PGSSubPictureReference { |
int x; |
int y; |
int picture_id; |
int composition; |
} PGSSubPictureReference; |
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typedef struct PGSSubPresentation { |
int id_number; |
int object_count; |
PGSSubPictureReference *objects; |
int64_t pts; |
} PGSSubPresentation; |
|
typedef struct PGSSubPicture { |
int w; |
int h; |
uint8_t *rle; |
unsigned int rle_buffer_size, rle_data_len; |
unsigned int rle_remaining_len; |
} PGSSubPicture; |
|
typedef struct PGSSubContext { |
AVClass *class; |
PGSSubPresentation presentation; |
uint32_t clut[256]; |
PGSSubPicture pictures[UINT16_MAX]; |
int forced_subs_only; |
} PGSSubContext; |
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static av_cold int init_decoder(AVCodecContext *avctx) |
{ |
avctx->pix_fmt = AV_PIX_FMT_PAL8; |
|
return 0; |
} |
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static av_cold int close_decoder(AVCodecContext *avctx) |
{ |
uint16_t picture; |
|
PGSSubContext *ctx = avctx->priv_data; |
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av_freep(&ctx->presentation.objects); |
ctx->presentation.object_count = 0; |
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for (picture = 0; picture < UINT16_MAX; ++picture) { |
av_freep(&ctx->pictures[picture].rle); |
ctx->pictures[picture].rle_buffer_size = 0; |
} |
|
return 0; |
} |
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/** |
* Decode the RLE data. |
* |
* The subtitle is stored as a Run Length Encoded image. |
* |
* @param avctx contains the current codec context |
* @param sub pointer to the processed subtitle data |
* @param buf pointer to the RLE data to process |
* @param buf_size size of the RLE data to process |
*/ |
static int decode_rle(AVCodecContext *avctx, AVSubtitle *sub, int rect, |
const uint8_t *buf, unsigned int buf_size) |
{ |
const uint8_t *rle_bitmap_end; |
int pixel_count, line_count; |
|
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]) |
return -1; |
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pixel_count = 0; |
line_count = 0; |
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while (buf < rle_bitmap_end && line_count < sub->rects[rect]->h) { |
uint8_t flags, color; |
int run; |
|
color = bytestream_get_byte(&buf); |
run = 1; |
|
if (color == 0x00) { |
flags = bytestream_get_byte(&buf); |
run = flags & 0x3f; |
if (flags & 0x40) |
run = (run << 8) + bytestream_get_byte(&buf); |
color = flags & 0x80 ? bytestream_get_byte(&buf) : 0; |
} |
|
if (run > 0 && pixel_count + run <= sub->rects[rect]->w * sub->rects[rect]->h) { |
memset(sub->rects[rect]->pict.data[0] + pixel_count, color, run); |
pixel_count += run; |
} else if (!run) { |
/* |
* New Line. Check if correct pixels decoded, if not display warning |
* and adjust bitmap pointer to correct new line position. |
*/ |
if (pixel_count % sub->rects[rect]->w > 0) |
av_log(avctx, AV_LOG_ERROR, "Decoded %d pixels, when line should be %d pixels\n", |
pixel_count % sub->rects[rect]->w, sub->rects[rect]->w); |
line_count++; |
} |
} |
|
if (pixel_count < sub->rects[rect]->w * sub->rects[rect]->h) { |
av_log(avctx, AV_LOG_ERROR, "Insufficient RLE data for subtitle\n"); |
return -1; |
} |
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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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/** |
* Parse the picture segment packet. |
* |
* The picture segment contains details on the sequence id, |
* width, height and Run Length Encoded (RLE) bitmap data. |
* |
* @param avctx contains the current codec context |
* @param buf pointer to the packet to process |
* @param buf_size size of packet to process |
* @todo TODO: Enable support for RLE data over multiple packets |
*/ |
static int parse_picture_segment(AVCodecContext *avctx, |
const uint8_t *buf, int buf_size) |
{ |
PGSSubContext *ctx = avctx->priv_data; |
|
uint8_t sequence_desc; |
unsigned int rle_bitmap_len, width, height; |
uint16_t picture_id; |
|
if (buf_size <= 4) |
return -1; |
buf_size -= 4; |
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picture_id = bytestream_get_be16(&buf); |
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/* skip 1 unknown byte: Version Number */ |
buf++; |
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/* Read the Sequence Description to determine if start of RLE data or appended to previous RLE */ |
sequence_desc = bytestream_get_byte(&buf); |
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if (!(sequence_desc & 0x80)) { |
/* Additional RLE data */ |
if (buf_size > ctx->pictures[picture_id].rle_remaining_len) |
return -1; |
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memcpy(ctx->pictures[picture_id].rle + ctx->pictures[picture_id].rle_data_len, buf, buf_size); |
ctx->pictures[picture_id].rle_data_len += buf_size; |
ctx->pictures[picture_id].rle_remaining_len -= buf_size; |
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return 0; |
} |
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if (buf_size <= 7) |
return -1; |
buf_size -= 7; |
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/* Decode rle bitmap length, stored size includes width/height data */ |
rle_bitmap_len = bytestream_get_be24(&buf) - 2*2; |
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/* Get bitmap dimensions from data */ |
width = bytestream_get_be16(&buf); |
height = bytestream_get_be16(&buf); |
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/* Make sure the bitmap is not too large */ |
if (avctx->width < width || avctx->height < height) { |
av_log(avctx, AV_LOG_ERROR, "Bitmap dimensions larger than video.\n"); |
return -1; |
} |
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if (buf_size > rle_bitmap_len) { |
av_log(avctx, AV_LOG_ERROR, "too much RLE data\n"); |
return AVERROR_INVALIDDATA; |
} |
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ctx->pictures[picture_id].w = width; |
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) |
return -1; |
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memcpy(ctx->pictures[picture_id].rle, buf, buf_size); |
ctx->pictures[picture_id].rle_data_len = buf_size; |
ctx->pictures[picture_id].rle_remaining_len = rle_bitmap_len - buf_size; |
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return 0; |
} |
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/** |
* Parse the palette segment packet. |
* |
* The palette segment contains details of the palette, |
* a maximum of 256 colors can be defined. |
* |
* @param avctx contains the current codec context |
* @param buf pointer to the packet to process |
* @param buf_size size of packet to process |
*/ |
static void parse_palette_segment(AVCodecContext *avctx, |
const uint8_t *buf, int buf_size) |
{ |
PGSSubContext *ctx = avctx->priv_data; |
|
const uint8_t *buf_end = buf + buf_size; |
const uint8_t *cm = ff_cropTbl + MAX_NEG_CROP; |
int color_id; |
int y, cb, cr, alpha; |
int r, g, b, r_add, g_add, b_add; |
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/* Skip two null bytes */ |
buf += 2; |
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while (buf < buf_end) { |
color_id = bytestream_get_byte(&buf); |
y = bytestream_get_byte(&buf); |
cr = bytestream_get_byte(&buf); |
cb = bytestream_get_byte(&buf); |
alpha = bytestream_get_byte(&buf); |
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YUV_TO_RGB1(cb, cr); |
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 */ |
ctx->clut[color_id] = RGBA(r,g,b,alpha); |
} |
} |
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/** |
* Parse the presentation segment packet. |
* |
* The presentation segment contains details on the video |
* width, video height, x & y subtitle position. |
* |
* @param avctx contains the current codec context |
* @param buf pointer to the packet to process |
* @param buf_size size of packet to process |
* @todo TODO: Implement cropping |
*/ |
static void parse_presentation_segment(AVCodecContext *avctx, |
const uint8_t *buf, int buf_size, |
int64_t pts) |
{ |
PGSSubContext *ctx = avctx->priv_data; |
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int w = bytestream_get_be16(&buf); |
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", |
w, h); |
if (av_image_check_size(w, h, 0, avctx) >= 0) |
avcodec_set_dimensions(avctx, w, h); |
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/* Skip 1 bytes of unknown, frame rate? */ |
buf++; |
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ctx->presentation.id_number = bytestream_get_be16(&buf); |
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/* |
* Skip 3 bytes of unknown: |
* state |
* palette_update_flag (0x80), |
* palette_id_to_use, |
*/ |
buf += 3; |
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ctx->presentation.object_count = bytestream_get_byte(&buf); |
if (!ctx->presentation.object_count) |
return; |
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/* Verify that enough bytes are remaining for all of the objects. */ |
buf_size -= 11; |
if (buf_size < ctx->presentation.object_count * 8) { |
ctx->presentation.object_count = 0; |
return; |
} |
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av_freep(&ctx->presentation.objects); |
ctx->presentation.objects = av_malloc(sizeof(PGSSubPictureReference) * ctx->presentation.object_count); |
if (!ctx->presentation.objects) { |
ctx->presentation.object_count = 0; |
return; |
} |
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for (object_index = 0; object_index < ctx->presentation.object_count; ++object_index) { |
PGSSubPictureReference *reference = &ctx->presentation.objects[object_index]; |
reference->picture_id = bytestream_get_be16(&buf); |
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/* Skip window_id_ref */ |
buf++; |
/* composition_flag (0x80 - object cropped, 0x40 - object forced) */ |
reference->composition = bytestream_get_byte(&buf); |
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reference->x = bytestream_get_be16(&buf); |
reference->y = bytestream_get_be16(&buf); |
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/* TODO If cropping, cropping_x, cropping_y, cropping_width, cropping_height (all 2 bytes).*/ |
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) { |
av_log(avctx, AV_LOG_ERROR, "Subtitle out of video bounds. x = %d, y = %d, video width = %d, video height = %d.\n", |
reference->x, reference->y, avctx->width, avctx->height); |
reference->x = 0; |
reference->y = 0; |
} |
} |
} |
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/** |
* Parse the display segment packet. |
* |
* The display segment controls the updating of the display. |
* |
* @param avctx contains the current codec context |
* @param data pointer to the data pertaining the subtitle to display |
* @param buf pointer to the packet to process |
* @param buf_size size of packet to process |
* @todo TODO: Fix start time, relies on correct PTS, currently too late |
* |
* @todo TODO: Fix end time, normally cleared by a second display |
* @todo segment, which is currently ignored as it clears |
* @todo the subtitle too early. |
*/ |
static int display_end_segment(AVCodecContext *avctx, void *data, |
const uint8_t *buf, int buf_size) |
{ |
AVSubtitle *sub = data; |
PGSSubContext *ctx = avctx->priv_data; |
int64_t pts; |
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uint16_t rect; |
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/* |
* The end display time is a timeout value and is only reached |
* if the next subtitle is later than timeout or subtitle has |
* not been cleared by a subsequent empty display command. |
*/ |
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pts = ctx->presentation.pts != AV_NOPTS_VALUE ? ctx->presentation.pts : sub->pts; |
memset(sub, 0, sizeof(*sub)); |
sub->pts = pts; |
ctx->presentation.pts = AV_NOPTS_VALUE; |
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// Blank if last object_count was 0. |
if (!ctx->presentation.object_count) |
return 1; |
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sub->start_display_time = 0; |
sub->end_display_time = 20000; |
sub->format = 0; |
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sub->num_rects = ctx->presentation.object_count; |
sub->rects = av_mallocz(sizeof(*sub->rects) * sub->num_rects); |
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for (rect = 0; rect < sub->num_rects; ++rect) { |
uint16_t picture_id = ctx->presentation.objects[rect].picture_id; |
sub->rects[rect] = av_mallocz(sizeof(*sub->rects[rect])); |
sub->rects[rect]->x = ctx->presentation.objects[rect].x; |
sub->rects[rect]->y = ctx->presentation.objects[rect].y; |
sub->rects[rect]->w = ctx->pictures[picture_id].w; |
sub->rects[rect]->h = ctx->pictures[picture_id].h; |
sub->rects[rect]->type = SUBTITLE_BITMAP; |
|
/* Process bitmap */ |
sub->rects[rect]->pict.linesize[0] = ctx->pictures[picture_id].w; |
if (ctx->pictures[picture_id].rle) { |
if (ctx->pictures[picture_id].rle_remaining_len) |
av_log(avctx, AV_LOG_ERROR, "RLE data length %u is %u bytes shorter than expected\n", |
ctx->pictures[picture_id].rle_data_len, ctx->pictures[picture_id].rle_remaining_len); |
if (decode_rle(avctx, sub, rect, ctx->pictures[picture_id].rle, ctx->pictures[picture_id].rle_data_len) < 0) |
return 0; |
} |
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/* Allocate memory for colors */ |
sub->rects[rect]->nb_colors = 256; |
sub->rects[rect]->pict.data[1] = av_mallocz(AVPALETTE_SIZE); |
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/* Copy the forced flag */ |
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) |
memcpy(sub->rects[rect]->pict.data[1], ctx->clut, sub->rects[rect]->nb_colors * sizeof(uint32_t)); |
} |
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return 1; |
} |
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static int decode(AVCodecContext *avctx, void *data, int *data_size, |
AVPacket *avpkt) |
{ |
const uint8_t *buf = avpkt->data; |
int buf_size = avpkt->size; |
AVSubtitle *sub = data; |
|
const uint8_t *buf_end; |
uint8_t segment_type; |
int segment_length; |
int i; |
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av_dlog(avctx, "PGS sub packet:\n"); |
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for (i = 0; i < buf_size; i++) { |
av_dlog(avctx, "%02x ", buf[i]); |
if (i % 16 == 15) |
av_dlog(avctx, "\n"); |
} |
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if (i & 15) |
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 */ |
if (buf_size < 3) |
return -1; |
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buf_end = buf + buf_size; |
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/* Step through buffer to identify segments */ |
while (buf < buf_end) { |
segment_type = bytestream_get_byte(&buf); |
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) |
break; |
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switch (segment_type) { |
case PALETTE_SEGMENT: |
parse_palette_segment(avctx, buf, segment_length); |
break; |
case PICTURE_SEGMENT: |
parse_picture_segment(avctx, buf, segment_length); |
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; |
} |
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return buf_size; |
} |
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#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 }, |
}; |
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static const AVClass pgsdec_class = { |
.class_name = "PGS subtitle decoder", |
.item_name = av_default_item_name, |
.option = options, |
.version = LIBAVUTIL_VERSION_INT, |
}; |
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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, |
}; |