From: Massimo Eynard <massimo.eynard@edu.univ-eiffel.fr>
To: ffmpeg-devel@ffmpeg.org
Subject: [FFmpeg-devel] [PATCH] libavcodec/pgssubdec: Implement cropping
Date: Tue, 4 Apr 2023 11:15:07 +0200
Message-ID: <c8f07db6-f096-61b3-e2d6-0c6f15dfb6a5@edu.univ-eiffel.fr> (raw)
In-Reply-To: <307774>
Implement missing cropping option of subtitle bitmap, enabling complex
cropping effects.
A test sample as been submitted to https://streams.videolan.org/upload/.
Attempt to correct the previous patch.
Signed-off-by: Massimo Eynard <massimo.eynard@edu.univ-eiffel.fr>
---
libavcodec/pgssubdec.c | 194 ++++++++++++++++++++++++++++-------------
1 file changed, 134 insertions(+), 60 deletions(-)
diff --git a/libavcodec/pgssubdec.c b/libavcodec/pgssubdec.c
index 5f76f12615..050667dbf3 100644
--- a/libavcodec/pgssubdec.c
+++ b/libavcodec/pgssubdec.c
@@ -70,9 +70,13 @@ typedef struct PGSSubObject {
int id;
int w;
int h;
- uint8_t *rle;
- unsigned int rle_buffer_size, rle_data_len;
+ uint8_t *rle; /**< Run Length Encoded bitmap. */
+ unsigned int rle_buffer_size;
+ unsigned int rle_data_len;
unsigned int rle_remaining_len;
+ uint8_t *bitmap; /**< Decoded bitmap. */
+ unsigned int bitmap_buffer_size;
+ unsigned int bitmap_size;
} PGSSubObject;
typedef struct PGSSubObjects {
@@ -105,8 +109,11 @@ static void flush_cache(AVCodecContext *avctx)
for (i = 0; i < ctx->objects.count; i++) {
av_freep(&ctx->objects.object[i].rle);
- ctx->objects.object[i].rle_buffer_size = 0;
+ ctx->objects.object[i].rle_buffer_size = 0;
ctx->objects.object[i].rle_remaining_len = 0;
+ av_freep(&ctx->objects.object[i].bitmap);
+ ctx->objects.object[i].bitmap_buffer_size = 0;
+ ctx->objects.object[i].bitmap_size = 0;
}
ctx->objects.count = 0;
ctx->palettes.count = 0;
@@ -149,57 +156,57 @@ static av_cold int close_decoder(AVCodecContext
*avctx)
}
/**
- * Decode the RLE data.
+ * Decode the RLE data of a subtitle object.
*
- * The subtitle is stored as a Run Length Encoded image.
+ * The subtitle is stored as a Run Length Encoded bitmap 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
+ * @param avctx Contains the current codec context.
+ * @param object Pointer to the processed subtitle object.
*/
-static int decode_rle(AVCodecContext *avctx, AVSubtitleRect *rect,
- const uint8_t *buf, unsigned int buf_size)
+static int decode_object_rle(AVCodecContext *avctx, PGSSubObject *object)
{
- const uint8_t *rle_bitmap_end;
+ const uint8_t *rle_buf;
+ const uint8_t *rle_end;
int pixel_count, line_count;
- rle_bitmap_end = buf + buf_size;
-
- rect->data[0] = av_malloc_array(rect->w, rect->h);
+ rle_buf = object->rle;
+ rle_end = object->rle + object->rle_data_len;
- if (!rect->data[0])
+ object->bitmap_size = object->w * object->h;
+ av_fast_padded_malloc(&object->bitmap, &object->bitmap_buffer_size,
object->bitmap_size);
+ if (!object->bitmap)
return AVERROR(ENOMEM);
pixel_count = 0;
line_count = 0;
- while (buf < rle_bitmap_end && line_count < rect->h) {
+ while (rle_buf < rle_end && line_count < object->h) {
uint8_t flags, color;
int run;
- color = bytestream_get_byte(&buf);
+ color = bytestream_get_byte(&rle_buf);
run = 1;
if (color == 0x00) {
- flags = bytestream_get_byte(&buf);
+ flags = bytestream_get_byte(&rle_buf);
run = flags & 0x3f;
if (flags & 0x40)
- run = (run << 8) + bytestream_get_byte(&buf);
- color = flags & 0x80 ? bytestream_get_byte(&buf) : 0;
+ run = (run << 8) + bytestream_get_byte(&rle_buf);
+ color = flags & 0x80 ? bytestream_get_byte(&rle_buf) : 0;
}
- if (run > 0 && pixel_count + run <= rect->w * rect->h) {
- memset(rect->data[0] + pixel_count, color, run);
+ if (run > 0 && pixel_count + run <= object->w * object->h) {
+ memset(object->bitmap + 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 % rect->w > 0) {
- av_log(avctx, AV_LOG_ERROR, "Decoded %d pixels, when
line should be %d pixels\n",
- pixel_count % rect->w, rect->w);
+ if (pixel_count % object->w > 0) {
+ av_log(avctx, AV_LOG_ERROR,
+ "Decoded %d pixels, when object line should be
%d pixels\n",
+ pixel_count % object->w, object->w);
if (avctx->err_recognition & AV_EF_EXPLODE) {
return AVERROR_INVALIDDATA;
}
@@ -208,12 +215,12 @@ static int decode_rle(AVCodecContext *avctx,
AVSubtitleRect *rect,
}
}
- if (pixel_count < rect->w * rect->h) {
- av_log(avctx, AV_LOG_ERROR, "Insufficient RLE data for
subtitle\n");
+ if (pixel_count < object->w * object->h) {
+ av_log(avctx, AV_LOG_ERROR, "Insufficient RLE data for object\n");
return AVERROR_INVALIDDATA;
}
- ff_dlog(avctx, "Pixel Count = %d, Area = %d\n", pixel_count,
rect->w * rect->h);
+ ff_dlog(avctx, "Pixel Count = %d, Area = %d\n", pixel_count,
object->w * object->h);
return 0;
}
@@ -289,14 +296,16 @@ static int parse_object_segment(AVCodecContext *avctx,
width = bytestream_get_be16(&buf);
height = bytestream_get_be16(&buf);
- /* Make sure the bitmap is not too large */
- if (avctx->width < width || avctx->height < height || !width ||
!height) {
- av_log(avctx, AV_LOG_ERROR, "Bitmap dimensions (%dx%d)
invalid.\n", width, height);
+ /* Make sure the bitmap size is not zero */
+ if (!width || !height) {
+ av_log(avctx, AV_LOG_ERROR,
+ "Bitmap dimensions (%dx%d) invalid.\n", width, height);
return AVERROR_INVALIDDATA;
}
object->w = width;
object->h = height;
+ /* Dimensions against video are checked at decode after cropping. */
av_fast_padded_malloc(&object->rle, &object->rle_buffer_size,
rle_bitmap_len);
@@ -383,7 +392,6 @@ static int parse_palette_segment(AVCodecContext
*avctx,
* @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 int parse_presentation_segment(AVCodecContext *avctx,
const uint8_t *buf, int buf_size,
@@ -468,16 +476,7 @@ static int
parse_presentation_segment(AVCodecContext *avctx,
ff_dlog(avctx, "Subtitle Placement x=%d, y=%d\n",
object->x, object->y);
-
- if (object->x > avctx->width || object->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",
- object->x, object->y,
- avctx->width, avctx->height);
- object->y = object->x = 0;
- if (avctx->err_recognition & AV_EF_EXPLODE) {
- return AVERROR_INVALIDDATA;
- }
- }
+ /* Placement is checked at decode after cropping. */
}
return 0;
@@ -528,6 +527,7 @@ static int display_end_segment(AVCodecContext
*avctx, AVSubtitle *sub,
return AVERROR_INVALIDDATA;
}
for (i = 0; i < ctx->presentation.object_count; i++) {
+ const PGSSubObjectRef sub_object = ctx->presentation.objects[i];
AVSubtitleRect *const rect = av_mallocz(sizeof(*rect));
PGSSubObject *object;
@@ -537,45 +537,119 @@ static int display_end_segment(AVCodecContext
*avctx, AVSubtitle *sub,
rect->type = SUBTITLE_BITMAP;
/* Process bitmap */
- object = find_object(ctx->presentation.objects[i].id,
&ctx->objects);
+ object = find_object(sub_object.id, &ctx->objects);
if (!object) {
// Missing object. Should only happen with damaged streams.
av_log(avctx, AV_LOG_ERROR, "Invalid object id %d\n",
- ctx->presentation.objects[i].id);
+ sub_object.id);
if (avctx->err_recognition & AV_EF_EXPLODE)
return AVERROR_INVALIDDATA;
// Leaves rect empty with 0 width and height.
continue;
}
- if (ctx->presentation.objects[i].composition_flag & 0x40)
+ if (sub_object.composition_flag & 0x40)
rect->flags |= AV_SUBTITLE_FLAG_FORCED;
- rect->x = ctx->presentation.objects[i].x;
- rect->y = ctx->presentation.objects[i].y;
+ rect->x = sub_object.x;
+ rect->y = sub_object.y;
if (object->rle) {
- rect->w = object->w;
- rect->h = object->h;
+ int out_of_picture = 0;
+ rect->w = object->w;
+ rect->h = object->h;
rect->linesize[0] = object->w;
- if (object->rle_remaining_len) {
- av_log(avctx, AV_LOG_ERROR, "RLE data length %u is %u
bytes shorter than expected\n",
- object->rle_data_len, object->rle_remaining_len);
+ // Check for cropping.
+ if (sub_object.composition_flag & 0x80) {
+ int out_of_object = 0;
+
+ if (object->w < sub_object.crop_x + sub_object.crop_w)
+ out_of_object = 1;
+ if (object->h < sub_object.crop_y + sub_object.crop_h)
+ out_of_object = 1;
+
+ if (out_of_object) {
+ av_log(avctx, AV_LOG_ERROR,
+ "Subtitle cropping values are out of object. "
+ "obj_w = %d, obj_h = %d, crop_x = %d, crop_y
= %d, "
+ "crop_w = %d, crop_h = %d.\n",
+ object->w,
+ object->h,
+ sub_object.crop_x,
+ sub_object.crop_y,
+ sub_object.crop_w,
+ sub_object.crop_h);
+ if (avctx->err_recognition & AV_EF_EXPLODE)
+ return AVERROR_INVALIDDATA;
+ }
+ else {
+ // Replace subtitle dimensions with cropping ones.
+ rect->w = sub_object.crop_w;
+ rect->h = sub_object.crop_h;
+ rect->linesize[0] = sub_object.crop_w;
+ }
+ }
+
+ /* Make sure the subtitle is not out of picture. */
+ if (avctx->width < rect->x + rect->w || !rect->w)
+ out_of_picture = 1;
+ if (avctx->height < rect->y + rect->h || !rect->h)
+ out_of_picture = 1;
+ if (out_of_picture) {
+ av_log(avctx, AV_LOG_ERROR,
+ "Subtitle out of video bounds. "
+ "x = %d, y = %d, width = %d, height = %d.\n",
+ rect->x, rect->y, rect->w, rect->h);
if (avctx->err_recognition & AV_EF_EXPLODE)
return AVERROR_INVALIDDATA;
- }
- ret = decode_rle(avctx, rect, object->rle,
object->rle_data_len);
- if (ret < 0) {
- if ((avctx->err_recognition & AV_EF_EXPLODE) ||
- ret == AVERROR(ENOMEM)) {
- return ret;
- }
rect->w = 0;
rect->h = 0;
continue;
}
+
+ if (!object->bitmap_size) {
+ /* Decode bitmap from RLE. */
+ if (object->rle_remaining_len) {
+ av_log(avctx, AV_LOG_ERROR,
+ "RLE data length %u is %u bytes shorter than
expected\n",
+ object->rle_data_len, object->rle_remaining_len);
+ if (avctx->err_recognition & AV_EF_EXPLODE)
+ return AVERROR_INVALIDDATA;
+ }
+
+ ret = decode_object_rle(avctx, object);
+ if (ret < 0) {
+ if ((avctx->err_recognition & AV_EF_EXPLODE) ||
+ ret == AVERROR(ENOMEM)) {
+ return ret;
+ }
+ rect->w = 0;
+ rect->h = 0;
+ continue;
+ }
+ }
+
+ rect->data[0] = av_malloc_array(rect->w, rect->h);
+ if (!rect->data[0])
+ return AVERROR(ENOMEM);
+
+ if (sub_object.composition_flag & 0x80) {
+ /* Copy cropped bitmap. */
+ int y;
+
+ for (y = 0; y < sub_object.crop_h; y++) {
+ memcpy(&rect->data[0][y * sub_object.crop_w],
+ &object->bitmap[(sub_object.crop_y + y) *
+ object->w + sub_object.crop_x],
+ sub_object.crop_w);
+ }
+ }
+ else {
+ memcpy(rect->data[0], object->bitmap, object->bitmap_size);
+ }
}
+
/* Allocate memory for colors */
rect->nb_colors = 256;
rect->data[1] = av_mallocz(AVPALETTE_SIZE);
--
2.40.0
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
next parent reply other threads:[~2023-04-04 9:15 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <307774>
2023-04-04 9:15 ` Massimo Eynard [this message]
2023-03-25 14:01 Massimo Eynard
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=c8f07db6-f096-61b3-e2d6-0c6f15dfb6a5@edu.univ-eiffel.fr \
--to=massimo.eynard@edu.univ-eiffel.fr \
--cc=ffmpeg-devel@ffmpeg.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Git Inbox Mirror of the ffmpeg-devel mailing list - see https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
This inbox may be cloned and mirrored by anyone:
git clone --mirror https://master.gitmailbox.com/ffmpegdev/0 ffmpegdev/git/0.git
# If you have public-inbox 1.1+ installed, you may
# initialize and index your mirror using the following commands:
public-inbox-init -V2 ffmpegdev ffmpegdev/ https://master.gitmailbox.com/ffmpegdev \
ffmpegdev@gitmailbox.com
public-inbox-index ffmpegdev
Example config snippet for mirrors.
AGPL code for this site: git clone https://public-inbox.org/public-inbox.git