On 06/13/2014 07:56 AM, John Stebbins wrote:
> Add ability to handle multiple palettes and objects simultaneously.
> Each simultaneous object is given its own AVSubtitleRect.
> Note that there can be up to 64 currently valid objects, but only
> 2 at any one time can be "presented".
> ---
> libavcodec/pgssubdec.c | 349
> +++++++++++++++++++++++++++++++++++--------------
> 1 file changed, 249 insertions(+), 100 deletions(-)
>
> diff --git a/libavcodec/pgssubdec.c b/libavcodec/pgssubdec.c
> index 4f175a3..e1df4cc 100644
> --- a/libavcodec/pgssubdec.c
> +++ b/libavcodec/pgssubdec.c
> @@ -33,38 +33,107 @@
> #include "libavutil/imgutils.h"
>
> #define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
> +#define MAX_EPOCH_PALETTES 8 // Max 8 allowed per PGS epoch
> +#define MAX_EPOCH_OBJECTS 64 // Max 64 allowed per PGS epoch
> +#define MAX_OBJECT_REFS 2 // Max objects per display set
>
> enum SegmentType {
> PALETTE_SEGMENT = 0x14,
> - PICTURE_SEGMENT = 0x15,
> + OBJECT_SEGMENT = 0x15,
> PRESENTATION_SEGMENT = 0x16,
> WINDOW_SEGMENT = 0x17,
> DISPLAY_SEGMENT = 0x80,
> };
>
> +typedef struct PGSSubObjectRef {
> + int id;
> + int window_id;
> + uint8_t composition_flag;
> + int x;
> + int y;
> + int crop_x;
> + int crop_y;
> + int crop_w;
> + int crop_h;
> +} PGSSubObjectRef;
> +
> typedef struct PGSSubPresentation {
> - int x;
> - int y;
> int id_number;
> - int object_number;
> - uint8_t composition_flag;
> + int palette_id;
> + int object_count;
> + PGSSubObjectRef objects[MAX_OBJECT_REFS];
> int64_t pts;
> } PGSSubPresentation;
>
> -typedef struct PGSSubPicture {
> +typedef struct PGSSubObject {
> + int id;
> int w;
> int h;
> uint8_t *rle;
> unsigned int rle_buffer_size, rle_data_len;
> unsigned int rle_remaining_len;
> -} PGSSubPicture;
> +} PGSSubObject;
> +
> +typedef struct PGSSubObjects {
> + int count;
> + PGSSubObject object[MAX_EPOCH_OBJECTS];
> +} PGSSubObjects;
> +
> +typedef struct PGSSubPalette {
> + int id;
> + uint32_t clut[256];
> +} PGSSubPalette;
> +
> +typedef struct PGSSubPalettes {
> + int count;
> + PGSSubPalette palette[MAX_EPOCH_PALETTES];
> +} PGSSubPalettes;
>
> typedef struct PGSSubContext {
> PGSSubPresentation presentation;
> - uint32_t clut[256];
> - PGSSubPicture picture;
> + PGSSubPalettes palettes;
> + PGSSubObjects objects;
> } PGSSubContext;
>
> +static void close_objects(PGSSubObjects *objects)
> +{
> + int i;
> +
> + for (i = 0; i < objects->count; i++) {
> + av_freep(&objects->object[i].rle);
> + objects->object[i].rle_buffer_size = 0;
> + objects->object[i].rle_remaining_len = 0;
> + }
> + objects->count = 0;
> +}
> +
> +static void close_palettes(PGSSubPalettes *palettes)
> +{
> + palettes->count = 0;
> +}
> +
> +static PGSSubObject * find_object(int id, PGSSubObjects *objects)
> +{
> + int i;
> +
> + for (i = 0; i < objects->count; i++) {
> + if (objects->object[i].id == id)
> + return &objects->object[i];
> + }
> + return NULL;
> +}
> +
> +static PGSSubPalette * find_palette(int id, PGSSubPalettes *palettes)
> +{
> + int i;
> +
> + for (i = 0; i < palettes->count; i++) {
> + if (palettes->palette[i].id == id)
> + return &palettes->palette[i];
> + }
> + return NULL;
> +}
> +
> static av_cold int init_decoder(AVCodecContext *avctx)
> {
> avctx->pix_fmt = AV_PIX_FMT_PAL8;
> @@ -76,8 +145,8 @@ static av_cold int close_decoder(AVCodecContext *avctx)
> {
> PGSSubContext *ctx = avctx->priv_data;
>
> - av_freep(&ctx->picture.rle);
> - ctx->picture.rle_buffer_size = 0;
> + close_objects(&ctx->objects);
> + close_palettes(&ctx->palettes);
>
> return 0;
> }
> @@ -92,7 +161,7 @@ static av_cold int close_decoder(AVCodecContext *avctx)
> * @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,
> +static int decode_rle(AVCodecContext *avctx, AVSubtitleRect *rect,
> const uint8_t *buf, unsigned int buf_size)
> {
> const uint8_t *rle_bitmap_end;
> @@ -100,15 +169,15 @@ static int decode_rle(AVCodecContext *avctx, AVSubtitle
> *sub,
>
> rle_bitmap_end = buf + buf_size;
>
> - sub->rects[0]->pict.data[0] = av_malloc(sub->rects[0]->w *
> sub->rects[0]->h);
> + rect->pict.data[0] = av_malloc(rect->w * rect->h);
>
> - if (!sub->rects[0]->pict.data[0])
> + if (!rect->pict.data[0])
> return -1;
>
> pixel_count = 0;
> line_count = 0;
>
> - while (buf < rle_bitmap_end && line_count < sub->rects[0]->h) {
> + while (buf < rle_bitmap_end && line_count < rect->h) {
> uint8_t flags, color;
> int run;
>
> @@ -123,27 +192,27 @@ static int decode_rle(AVCodecContext *avctx, AVSubtitle
> *sub,
> color = flags & 0x80 ? bytestream_get_byte(&buf) : 0;
> }
>
> - if (run > 0 && pixel_count + run <= sub->rects[0]->w *
> sub->rects[0]->h) {
> - memset(sub->rects[0]->pict.data[0] + pixel_count, color, run);
> + if (run > 0 && pixel_count + run <= rect->w * rect->h) {
> + memset(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[0]->w > 0)
> + if (pixel_count % rect->w > 0)
> av_log(avctx, AV_LOG_ERROR, "Decoded %d pixels, when line
> should be %d pixels\n",
> - pixel_count % sub->rects[0]->w, sub->rects[0]->w);
> + pixel_count % rect->w, rect->w);
> line_count++;
> }
> }
>
> - if (pixel_count < sub->rects[0]->w * sub->rects[0]->h) {
> + if (pixel_count < rect->w * rect->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);
> + av_dlog(avctx, "Pixel Count = %d, Area = %d\n", pixel_count, rect->w *
> rect->h);
>
> return 0;
> }
> @@ -159,32 +228,45 @@ static int decode_rle(AVCodecContext *avctx, AVSubtitle
> *sub,
> * @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,
> +static int parse_object_segment(AVCodecContext *avctx,
> const uint8_t *buf, int buf_size)
> {
> PGSSubContext *ctx = avctx->priv_data;
> + PGSSubObject *object;
>
> uint8_t sequence_desc;
> unsigned int rle_bitmap_len, width, height;
> + int id;
>
> if (buf_size <= 4)
> return -1;
> buf_size -= 4;
>
> - /* skip 3 unknown bytes: Object ID (2 bytes), Version Number */
> - buf += 3;
> + id = bytestream_get_be16(&buf);
> + object = find_object(id, &ctx->objects);
> + if (!object) {
> + if (ctx->objects.count >= MAX_EPOCH_OBJECTS) {
> + av_log(avctx, AV_LOG_ERROR, "Too many objects in epoch\n");
> + return -1;
> + }
> + object = &ctx->objects.object[ctx->objects.count++];
> + object->id = id;
> + }
> +
> + /* skip object version number */
> + buf += 1;
>
> /* Read the Sequence Description to determine if start of RLE data or
> appended to previous RLE */
> sequence_desc = bytestream_get_byte(&buf);
>
> if (!(sequence_desc & 0x80)) {
> /* Additional RLE data */
> - if (buf_size > ctx->picture.rle_remaining_len)
> + if (buf_size > object->rle_remaining_len)
> return -1;
>
> - 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;
> + memcpy(object->rle + object->rle_data_len, buf, buf_size);
> + object->rle_data_len += buf_size;
> + object->rle_remaining_len -= buf_size;
>
> return 0;
> }
> @@ -206,17 +288,17 @@ static int parse_picture_segment(AVCodecContext *avctx,
> return -1;
> }
>
> - ctx->picture.w = width;
> - ctx->picture.h = height;
> + object->w = width;
> + object->h = height;
>
> - av_fast_malloc(&ctx->picture.rle, &ctx->picture.rle_buffer_size,
> rle_bitmap_len);
> + av_fast_malloc(&object->rle, &object->rle_buffer_size, rle_bitmap_len);
>
> - if (!ctx->picture.rle)
> + if (!object->rle)
> return -1;
>
> - memcpy(ctx->picture.rle, buf, buf_size);
> - ctx->picture.rle_data_len = buf_size;
> - ctx->picture.rle_remaining_len = rle_bitmap_len - buf_size;
> + memcpy(object->rle, buf, buf_size);
> + object->rle_data_len = buf_size;
> + object->rle_remaining_len = rle_bitmap_len - buf_size;
>
> return 0;
> }
> @@ -231,19 +313,32 @@ static int parse_picture_segment(AVCodecContext *avctx,
> * @param buf pointer to the packet to process
> * @param buf_size size of packet to process
> */
> -static void parse_palette_segment(AVCodecContext *avctx,
> +static int parse_palette_segment(AVCodecContext *avctx,
> const uint8_t *buf, int buf_size)
> {
> PGSSubContext *ctx = avctx->priv_data;
> + PGSSubPalette *palette;
>
> const uint8_t *buf_end = buf + buf_size;
> const uint8_t *cm = ff_crop_tab + MAX_NEG_CROP;
> int color_id;
> int y, cb, cr, alpha;
> int r, g, b, r_add, g_add, b_add;
> + int id;
>
> - /* Skip two null bytes */
> - buf += 2;
> + id = bytestream_get_byte(&buf);
> + palette = find_palette(id, &ctx->palettes);
> + if (!palette) {
> + if (ctx->palettes.count >= MAX_EPOCH_PALETTES) {
> + av_log(avctx, AV_LOG_ERROR, "Too many palettes in epoch\n");
> + return -1;
> + }
> + palette = &ctx->palettes.palette[ctx->palettes.count++];
> + palette->id = id;
> + }
> +
> + /* Skip palette version */
> + buf += 1;
>
> while (buf < buf_end) {
> color_id = bytestream_get_byte(&buf);
> @@ -258,8 +353,9 @@ static void parse_palette_segment(AVCodecContext *avctx,
> 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);
> + palette->clut[color_id] = RGBA(r,g,b,alpha);
> }
> + return 0;
> }
>
> /**
> @@ -280,8 +376,9 @@ static int parse_presentation_segment(AVCodecContext
> *avctx,
> {
> PGSSubContext *ctx = avctx->priv_data;
>
> - int x, y, ret;
> + int i, state, ret;
>
> + // Video descriptor
> int w = bytestream_get_be16(&buf);
> int h = bytestream_get_be16(&buf);
>
> @@ -293,49 +390,70 @@ static int parse_presentation_segment(AVCodecContext
> *avctx,
> if (ret < 0)
> return ret;
>
> - /* Skip 1 bytes of unknown, frame rate? */
> + /* Skip 1 bytes of unknown, frame rate */
> buf++;
>
> + // Composition descriptor
> ctx->presentation.id_number = bytestream_get_be16(&buf);
> -
> /*
> - * Skip 3 bytes of unknown:
> - * state
> - * palette_update_flag (0x80),
> - * palette_id_to_use,
> + * state is a 2 bit field that defines pgs epoch boundaries
> + * 00 - Normal, previously defined objects and palettes are still valid
> + * 01 - Acquisition point, previous objects and palettes can be released
> + * 10 - Epoch start, previous objects and palettes can be released
> + * 11 - Epoch continue, previous objects and palettes can be released
> + *
> + * reserved 6 bits discarded
> */
> - buf += 3;
> -
> - ctx->presentation.object_number = bytestream_get_byte(&buf);
> - ctx->presentation.composition_flag = 0;
> - if (!ctx->presentation.object_number)
> - return 0;
> + state = bytestream_get_byte(&buf) >> 6;
> + if (state != 0) {
> + close_objects(&ctx->objects);
> + close_palettes(&ctx->palettes);
> + }
>
> /*
> - * Skip 3 bytes of unknown:
> - * object_id_ref (2 bytes),
> - * window_id_ref,
> + * skip palette_update_flag (0x80),
> */
> - buf += 3;
> - ctx->presentation.composition_flag = bytestream_get_byte(&buf);
> -
> - x = bytestream_get_be16(&buf);
> - y = bytestream_get_be16(&buf);
> -
> - /* TODO If cropping, cropping_x, cropping_y, cropping_width,
> cropping_height (all 2 bytes).*/
> + buf += 1;
> + ctx->presentation.palette_id = bytestream_get_byte(&buf);
> + ctx->presentation.object_count = bytestream_get_byte(&buf);
> + if (ctx->presentation.object_count > MAX_OBJECT_REFS) {
> + av_log(avctx, AV_LOG_ERROR,
> + "Invalid number of presentation objects %d\n",
> + ctx->presentation.object_count);
> + ctx->presentation.object_count = 2;
> + }
>
> - av_dlog(avctx, "Subtitle Placement x=%d, y=%d\n", x, y);
> + for (i = 0; i < ctx->presentation.object_count; i++)
> + {
> + ctx->presentation.objects[i].id = bytestream_get_be16(&buf);
> + ctx->presentation.objects[i].window_id = bytestream_get_byte(&buf);
> + ctx->presentation.objects[i].composition_flag =
> bytestream_get_byte(&buf);
> +
> + ctx->presentation.objects[i].x = bytestream_get_be16(&buf);
> + ctx->presentation.objects[i].y = bytestream_get_be16(&buf);
> +
> + // If cropping
> + if (ctx->presentation.objects[i].composition_flag & 0x80) {
> + ctx->presentation.objects[i].crop_x = bytestream_get_be16(&buf);
> + ctx->presentation.objects[i].crop_y = bytestream_get_be16(&buf);
> + ctx->presentation.objects[i].crop_w = bytestream_get_be16(&buf);
> + ctx->presentation.objects[i].crop_h = bytestream_get_be16(&buf);
> + }
>
> - 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;
> + av_dlog(avctx, "Subtitle Placement x=%d, y=%d\n",
> + ctx->presentation.objects[i].x,
> ctx->presentation.objects[i].y);
> +
> + if (ctx->presentation.objects[i].x > avctx->width ||
> + ctx->presentation.objects[i].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",
> + ctx->presentation.objects[i].x,
> + ctx->presentation.objects[i].y,
> + avctx->width, avctx->height);
> + ctx->presentation.objects[i].x = 0;
> + ctx->presentation.objects[i].y = 0;
> + }
> }
>
> - /* Fill in dimensions */
> - ctx->presentation.x = x;
> - ctx->presentation.y = y;
> -
> return 0;
> }
>
> @@ -359,6 +477,8 @@ static int display_end_segment(AVCodecContext *avctx,
> void *data,
> {
> AVSubtitle *sub = data;
> PGSSubContext *ctx = avctx->priv_data;
> + PGSSubPalette *palette;
> + int i;
>
> /*
> * The end display time is a timeout value and is only reached
> @@ -369,43 +489,72 @@ static int display_end_segment(AVCodecContext *avctx,
> void *data,
> memset(sub, 0, sizeof(*sub));
> sub->pts = ctx->presentation.pts;
>
> - // Blank if last object_number was 0.
> + // Blank if last object_count was 0.
> // Note that this may be wrong for more complex subtitles.
> - if (!ctx->presentation.object_number)
> + if (!ctx->presentation.object_count)
> return 1;
> sub->start_display_time = 0;
> sub->end_display_time = 20000;
> sub->format = 0;
>
> - sub->rects = av_mallocz(sizeof(*sub->rects));
> - sub->rects[0] = av_mallocz(sizeof(*sub->rects[0]));
> - sub->num_rects = 1;
> -
> - if (ctx->presentation.composition_flag & 0x40)
> - sub->rects[0]->flags |= AV_SUBTITLE_FLAG_FORCED;
> + sub->num_rects = ctx->presentation.object_count;
> + sub->rects = av_mallocz(sizeof(*sub->rects) * sub->num_rects);
> + if (!sub->rects) {
> + return -1;
> + }
> + palette = find_palette(ctx->presentation.palette_id, &ctx->palettes);
> + if (!palette) {
> + // Missing palette. Should only happen with damaged streams.
> + // TODO: use a default palette?
> + av_log(avctx, AV_LOG_ERROR, "Invalid palette id %d\n",
> + ctx->presentation.palette_id);
> + sub->num_rects = 0;
> + av_freep(&sub->rects);
> + return -1;
> + }
I changed the code above from the previous iteration of this patch because it
left the AVSubtitle in a bad state which
could lead to a crash.
> + for (i = 0; i < ctx->presentation.object_count; i++) {
> + PGSSubObject *object;
>
> - sub->rects[0]->x = ctx->presentation.x;
> - sub->rects[0]->y = ctx->presentation.y;
> - sub->rects[0]->w = ctx->picture.w;
> - sub->rects[0]->h = ctx->picture.h;
> - sub->rects[0]->type = SUBTITLE_BITMAP;
> + sub->rects[i] = av_mallocz(sizeof(*sub->rects[0]));
> + if (!sub->rects[i]) {
> + sub->num_rects = i;
> + return -1;
> + }
> + sub->rects[i]->type = SUBTITLE_BITMAP;
> +
> + /* Process bitmap */
> + object = find_object(ctx->presentation.objects[i].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);
> + // Leaves rect empty with 0 width and height.
> + continue;
> + }
ditto
> + if (ctx->presentation.objects[i].composition_flag & 0x40)
> + sub->rects[i]->flags |= AV_SUBTITLE_FLAG_FORCED;
> +
> + sub->rects[i]->x = ctx->presentation.objects[i].x;
> + sub->rects[i]->y = ctx->presentation.objects[i].y;
> + sub->rects[i]->w = object->w;
> + sub->rects[i]->h = object->h;
> +
> + sub->rects[i]->pict.linesize[0] = object->w;
> +
> + if (object->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(decode_rle(avctx, sub->rects[i], object->rle,
> object->rle_data_len) < 0)
> + return 0;
> + }
> + /* Allocate memory for colors */
> + sub->rects[i]->nb_colors = 256;
> + sub->rects[i]->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
>
> - /* Process bitmap */
> - sub->rects[0]->pict.linesize[0] = ctx->picture.w;
> + memcpy(sub->rects[i]->pict.data[1], palette->clut,
> sub->rects[i]->nb_colors * sizeof(uint32_t));
>
> - 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_mallocz(AVPALETTE_SIZE);
> -
> - memcpy(sub->rects[0]->pict.data[1], ctx->clut, sub->rects[0]->nb_colors
> * sizeof(uint32_t));
> -
> return 1;
> }
>
> @@ -453,8 +602,8 @@ static int decode(AVCodecContext *avctx, void *data, int
> *data_size,
> case PALETTE_SEGMENT:
> parse_palette_segment(avctx, buf, segment_length);
> break;
> - case PICTURE_SEGMENT:
> - parse_picture_segment(avctx, buf, segment_length);
> + case OBJECT_SEGMENT:
> + parse_object_segment(avctx, buf, segment_length);
> break;
> case PRESENTATION_SEGMENT:
> ret = parse_presentation_segment(avctx, buf, segment_length,
> avpkt->pts);
--
John GnuPG fingerprint: D0EC B3DB C372 D1F1 0B01 83F0 49F1 D7B2 60D4 D0F7
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