mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-23 12:43:46 +02:00
Improve support for PGS subtitles.
The previous implementation assumed that a new picture would always supersede the previous picture. Similarly, presentation segments were assumed to pertain to the most-recently-read picture. However, each presentation segment may refer to 0 or more pictures by their ID. Picture IDs may repeat, and a repeated picture ID indicates that the old picture for that ID is no longer needed and may be discarded. The new implementation allocates a buffer with one slot for each possible picture ID (the picture ID is a 16-bit field) and properly decodes presentation segments so that all relevant pictures are output upon encountering a display segment. Given that most PGS streams are unlikely to use more than a small fraction of the available picture IDs, it would probably be better to use a more memory-efficient data structure. I'm lazy though, so I leave this to a more motivated individual. I've tested the code with MKV files in VLC (a recent revision from their git repo) and with HandBrake (a version that I hacked up to use ffmpeg's PGS subtitle decoder). Review-by: Hendrik Leppkes <h.leppkes@gmail.com> Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
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@ -26,6 +26,7 @@ version next:
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- ffprobe -show_program_version, -show_library_versions, -show_versions options
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- ffprobe -show_program_version, -show_library_versions, -show_versions options
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- rv34: frame-level multi-threading
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- rv34: frame-level multi-threading
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- optimized iMDCT transform on x86 using SSE for for mpegaudiodec
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- optimized iMDCT transform on x86 using SSE for for mpegaudiodec
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- Improved PGS subtitle decoder
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version 0.9:
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version 0.9:
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@ -40,11 +40,16 @@ enum SegmentType {
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DISPLAY_SEGMENT = 0x80,
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DISPLAY_SEGMENT = 0x80,
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};
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};
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typedef struct PGSSubPresentation {
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typedef struct PGSSubPictureReference {
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int x;
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int x;
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int y;
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int y;
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int id_number;
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int picture_id;
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int object_number;
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} PGSSubPictureReference;
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typedef struct PGSSubPresentation {
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int id_number;
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int object_count;
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PGSSubPictureReference *objects;
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} PGSSubPresentation;
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} PGSSubPresentation;
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typedef struct PGSSubPicture {
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typedef struct PGSSubPicture {
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@ -58,22 +63,29 @@ typedef struct PGSSubPicture {
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typedef struct PGSSubContext {
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typedef struct PGSSubContext {
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PGSSubPresentation presentation;
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PGSSubPresentation presentation;
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uint32_t clut[256];
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uint32_t clut[256];
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PGSSubPicture picture;
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PGSSubPicture pictures[UINT16_MAX];
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} PGSSubContext;
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} PGSSubContext;
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static av_cold int init_decoder(AVCodecContext *avctx)
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static av_cold int init_decoder(AVCodecContext *avctx)
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{
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{
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avctx->pix_fmt = PIX_FMT_PAL8;
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avctx->pix_fmt = PIX_FMT_PAL8;
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return 0;
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return 0;
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}
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}
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static av_cold int close_decoder(AVCodecContext *avctx)
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static av_cold int close_decoder(AVCodecContext *avctx)
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{
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{
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uint16_t picture;
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PGSSubContext *ctx = avctx->priv_data;
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PGSSubContext *ctx = avctx->priv_data;
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av_freep(&ctx->picture.rle);
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av_freep(&ctx->presentation.objects);
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ctx->picture.rle_buffer_size = 0;
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ctx->presentation.object_count = 0;
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for (picture = 0; picture < UINT16_MAX; ++picture) {
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av_freep(&ctx->pictures[picture].rle);
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ctx->pictures[picture].rle_buffer_size = 0;
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}
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return 0;
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return 0;
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}
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}
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@ -88,7 +100,7 @@ static av_cold int close_decoder(AVCodecContext *avctx)
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* @param buf pointer to the RLE data to process
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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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* @param buf_size size of the RLE data to process
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*/
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*/
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static int decode_rle(AVCodecContext *avctx, AVSubtitle *sub,
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static int decode_rle(AVCodecContext *avctx, AVSubtitle *sub, int rect,
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const uint8_t *buf, unsigned int buf_size)
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const uint8_t *buf, unsigned int buf_size)
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{
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{
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const uint8_t *rle_bitmap_end;
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const uint8_t *rle_bitmap_end;
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@ -96,15 +108,15 @@ static int decode_rle(AVCodecContext *avctx, AVSubtitle *sub,
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rle_bitmap_end = buf + buf_size;
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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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sub->rects[rect]->pict.data[0] = av_malloc(sub->rects[rect]->w * sub->rects[rect]->h);
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if (!sub->rects[0]->pict.data[0])
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if (!sub->rects[rect]->pict.data[0])
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return -1;
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return -1;
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pixel_count = 0;
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pixel_count = 0;
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line_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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while (buf < rle_bitmap_end && line_count < sub->rects[rect]->h) {
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uint8_t flags, color;
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uint8_t flags, color;
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int run;
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int run;
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@ -119,27 +131,27 @@ static int decode_rle(AVCodecContext *avctx, AVSubtitle *sub,
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color = flags & 0x80 ? bytestream_get_byte(&buf) : 0;
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color = flags & 0x80 ? bytestream_get_byte(&buf) : 0;
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}
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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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if (run > 0 && pixel_count + run <= sub->rects[rect]->w * sub->rects[rect]->h) {
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memset(sub->rects[0]->pict.data[0] + pixel_count, color, run);
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memset(sub->rects[rect]->pict.data[0] + pixel_count, color, run);
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pixel_count += run;
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pixel_count += run;
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} else if (!run) {
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} else if (!run) {
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/*
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/*
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* New Line. Check if correct pixels decoded, if not display warning
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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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* and adjust bitmap pointer to correct new line position.
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*/
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*/
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if (pixel_count % sub->rects[0]->w > 0)
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if (pixel_count % sub->rects[rect]->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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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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pixel_count % sub->rects[rect]->w, sub->rects[rect]->w);
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line_count++;
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line_count++;
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}
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}
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}
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}
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if (pixel_count < sub->rects[0]->w * sub->rects[0]->h) {
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if (pixel_count < sub->rects[rect]->w * sub->rects[rect]->h) {
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av_log(avctx, AV_LOG_ERROR, "Insufficient RLE data for subtitle\n");
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av_log(avctx, AV_LOG_ERROR, "Insufficient RLE data for subtitle\n");
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return -1;
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return -1;
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}
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}
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av_dlog(avctx, "Pixel Count = %d, Area = %d\n", pixel_count, sub->rects[0]->w * sub->rects[0]->h);
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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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return 0;
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}
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}
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@ -162,25 +174,28 @@ static int parse_picture_segment(AVCodecContext *avctx,
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uint8_t sequence_desc;
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uint8_t sequence_desc;
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unsigned int rle_bitmap_len, width, height;
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unsigned int rle_bitmap_len, width, height;
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uint16_t picture_id;
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if (buf_size <= 4)
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if (buf_size <= 4)
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return -1;
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return -1;
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buf_size -= 4;
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buf_size -= 4;
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/* skip 3 unknown bytes: Object ID (2 bytes), Version Number */
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picture_id = bytestream_get_be16(&buf);
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buf += 3;
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/* skip 1 unknown byte: Version Number */
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buf++;
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/* Read the Sequence Description to determine if start of RLE data or appended to previous RLE */
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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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sequence_desc = bytestream_get_byte(&buf);
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if (!(sequence_desc & 0x80)) {
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if (!(sequence_desc & 0x80)) {
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/* Additional RLE data */
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/* Additional RLE data */
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if (buf_size > ctx->picture.rle_remaining_len)
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if (buf_size > ctx->pictures[picture_id].rle_remaining_len)
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return -1;
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return -1;
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memcpy(ctx->picture.rle + ctx->picture.rle_data_len, buf, buf_size);
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memcpy(ctx->pictures[picture_id].rle + ctx->pictures[picture_id].rle_data_len, buf, buf_size);
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ctx->picture.rle_data_len += buf_size;
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ctx->pictures[picture_id].rle_data_len += buf_size;
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ctx->picture.rle_remaining_len -= buf_size;
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ctx->pictures[picture_id].rle_remaining_len -= buf_size;
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return 0;
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return 0;
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}
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}
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@ -202,17 +217,17 @@ static int parse_picture_segment(AVCodecContext *avctx,
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return -1;
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return -1;
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}
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}
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ctx->picture.w = width;
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ctx->pictures[picture_id].w = width;
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ctx->picture.h = height;
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ctx->pictures[picture_id].h = height;
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av_fast_malloc(&ctx->picture.rle, &ctx->picture.rle_buffer_size, rle_bitmap_len);
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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->picture.rle)
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if (!ctx->pictures[picture_id].rle)
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return -1;
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return -1;
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memcpy(ctx->picture.rle, buf, buf_size);
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memcpy(ctx->pictures[picture_id].rle, buf, buf_size);
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ctx->picture.rle_data_len = buf_size;
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ctx->pictures[picture_id].rle_data_len = buf_size;
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ctx->picture.rle_remaining_len = rle_bitmap_len - buf_size;
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ctx->pictures[picture_id].rle_remaining_len = rle_bitmap_len - buf_size;
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return 0;
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return 0;
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}
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}
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@ -275,11 +290,11 @@ static void parse_presentation_segment(AVCodecContext *avctx,
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{
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{
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PGSSubContext *ctx = avctx->priv_data;
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PGSSubContext *ctx = avctx->priv_data;
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int x, y;
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int w = bytestream_get_be16(&buf);
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int w = bytestream_get_be16(&buf);
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int h = bytestream_get_be16(&buf);
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int h = bytestream_get_be16(&buf);
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uint16_t object_index;
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av_dlog(avctx, "Video Dimensions %dx%d\n",
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av_dlog(avctx, "Video Dimensions %dx%d\n",
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w, h);
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w, h);
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if (av_image_check_size(w, h, 0, avctx) >= 0)
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if (av_image_check_size(w, h, 0, avctx) >= 0)
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@ -298,34 +313,48 @@ static void parse_presentation_segment(AVCodecContext *avctx,
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*/
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*/
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buf += 3;
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buf += 3;
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ctx->presentation.object_number = bytestream_get_byte(&buf);
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ctx->presentation.object_count = bytestream_get_byte(&buf);
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if (!ctx->presentation.object_number)
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if (!ctx->presentation.object_count)
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return;
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return;
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/*
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/* Verify that enough bytes are remaining for all of the objects. */
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* Skip 4 bytes of unknown:
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buf_size -= 11;
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* object_id_ref (2 bytes),
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if (buf_size < ctx->presentation.object_count * 8) {
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* window_id_ref,
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ctx->presentation.object_count = 0;
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* composition_flag (0x80 - object cropped, 0x40 - object forced)
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return;
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*/
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buf += 4;
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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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av_dlog(avctx, "Subtitle Placement x=%d, y=%d\n", x, y);
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if (x > avctx->width || y > avctx->height) {
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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, avctx->width, avctx->height);
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x = 0; y = 0;
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}
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}
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/* Fill in dimensions */
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av_freep(&ctx->presentation.objects);
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ctx->presentation.x = x;
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ctx->presentation.objects = av_malloc(sizeof(PGSSubPictureReference) * ctx->presentation.object_count);
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ctx->presentation.y = y;
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if (!ctx->presentation.objects) {
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ctx->presentation.object_count = 0;
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return;
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}
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for (object_index = 0; object_index < ctx->presentation.object_count; ++object_index) {
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PGSSubPictureReference *reference = &ctx->presentation.objects[object_index];
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reference->picture_id = bytestream_get_be16(&buf);
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/*
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* Skip 2 bytes of unknown:
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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 += 2;
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reference->x = bytestream_get_be16(&buf);
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reference->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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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) {
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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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reference->x, reference->y, avctx->width, avctx->height);
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reference->x = 0;
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reference->y = 0;
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}
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}
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}
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}
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/**
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/**
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@ -349,45 +378,52 @@ static int display_end_segment(AVCodecContext *avctx, void *data,
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AVSubtitle *sub = data;
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AVSubtitle *sub = data;
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PGSSubContext *ctx = avctx->priv_data;
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PGSSubContext *ctx = avctx->priv_data;
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uint16_t rect;
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/*
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/*
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* The end display time is a timeout value and is only reached
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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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* if the next subtitle is later than timeout or subtitle has
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* not been cleared by a subsequent empty display command.
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* not been cleared by a subsequent empty display command.
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*/
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*/
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// Blank if last object_number was 0.
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memset(sub, 0, sizeof(*sub));
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// Note that this may be wrong for more complex subtitles.
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if (!ctx->presentation.object_number)
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// Blank if last object_count was 0.
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if (!ctx->presentation.object_count)
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return 1;
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return 1;
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sub->start_display_time = 0;
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sub->start_display_time = 0;
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sub->end_display_time = 20000;
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sub->end_display_time = 20000;
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sub->format = 0;
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sub->format = 0;
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sub->rects = av_mallocz(sizeof(*sub->rects));
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sub->num_rects = ctx->presentation.object_count;
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sub->rects[0] = av_mallocz(sizeof(*sub->rects[0]));
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sub->rects = av_mallocz(sizeof(*sub->rects) * sub->num_rects);
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sub->num_rects = 1;
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sub->rects[0]->x = ctx->presentation.x;
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for (rect = 0; rect < sub->num_rects; ++rect) {
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sub->rects[0]->y = ctx->presentation.y;
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uint16_t picture_id = ctx->presentation.objects[rect].picture_id;
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sub->rects[0]->w = ctx->picture.w;
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sub->rects[rect] = av_mallocz(sizeof(*sub->rects[rect]));
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sub->rects[0]->h = ctx->picture.h;
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sub->rects[rect]->x = ctx->presentation.objects[rect].x;
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sub->rects[0]->type = SUBTITLE_BITMAP;
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sub->rects[rect]->y = ctx->presentation.objects[rect].y;
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sub->rects[rect]->w = ctx->pictures[picture_id].w;
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sub->rects[rect]->h = ctx->pictures[picture_id].h;
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sub->rects[rect]->type = SUBTITLE_BITMAP;
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/* Process bitmap */
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/* Process bitmap */
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sub->rects[0]->pict.linesize[0] = ctx->picture.w;
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sub->rects[rect]->pict.linesize[0] = ctx->pictures[picture_id].w;
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if (ctx->pictures[picture_id].rle) {
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if (ctx->pictures[picture_id].rle_remaining_len)
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av_log(avctx, AV_LOG_ERROR, "RLE data length %u is %u bytes shorter than expected\n",
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||||||
|
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;
|
||||||
|
}
|
||||||
|
|
||||||
if (ctx->picture.rle) {
|
/* Allocate memory for colors */
|
||||||
if (ctx->picture.rle_remaining_len)
|
sub->rects[rect]->nb_colors = 256;
|
||||||
av_log(avctx, AV_LOG_ERROR, "RLE data length %u is %u bytes shorter than expected\n",
|
sub->rects[rect]->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
|
||||||
ctx->picture.rle_data_len, ctx->picture.rle_remaining_len);
|
|
||||||
if(decode_rle(avctx, sub, ctx->picture.rle, ctx->picture.rle_data_len) < 0)
|
memcpy(sub->rects[rect]->pict.data[1], ctx->clut, sub->rects[rect]->nb_colors * sizeof(uint32_t));
|
||||||
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;
|
return 1;
|
||||||
}
|
}
|
||||||
|
Loading…
Reference in New Issue
Block a user