---
libavcodec/pictordec.c | 99 +++++++++++++++++++++++++++--------------------
1 files changed, 57 insertions(+), 42 deletions(-)
diff --git a/libavcodec/pictordec.c b/libavcodec/pictordec.c
index 732583e..1856e8d 100644
--- a/libavcodec/pictordec.c
+++ b/libavcodec/pictordec.c
@@ -33,6 +33,7 @@ typedef struct PicContext {
AVFrame frame;
int width, height;
int nb_planes;
+ GetByteContext g;
} PicContext;
static void picmemset_8bpp(PicContext *s, int value, int run, int *x, int *y)
@@ -99,34 +100,33 @@ static int decode_frame(AVCodecContext *avctx,
AVPacket *avpkt)
{
PicContext *s = avctx->priv_data;
- int buf_size = avpkt->size;
- const uint8_t *buf = avpkt->data;
- const uint8_t *buf_end = avpkt->data + buf_size;
uint32_t *palette;
- int bits_per_plane, bpp, etype, esize, npal;
+ int bits_per_plane, bpp, etype, esize, npal, pos_after_pal;
int i, x, y, plane;
- if (buf_size < 11)
+ bytestream2_init(&s->g, avpkt->data, avpkt->size);
+
+ if (bytestream2_get_bytes_left(&s->g) < 11)
return AVERROR_INVALIDDATA;
- if (bytestream_get_le16(&buf) != 0x1234)
+ if (bytestream2_get_le16(&s->g) != 0x1234)
return AVERROR_INVALIDDATA;
- s->width = bytestream_get_le16(&buf);
- s->height = bytestream_get_le16(&buf);
- buf += 4;
- bits_per_plane = *buf & 0xF;
- s->nb_planes = (*buf++ >> 4) + 1;
- bpp = s->nb_planes ? bits_per_plane*s->nb_planes :
bits_per_plane;
+ s->width = bytestream2_get_le16(&s->g);
+ s->height = bytestream2_get_le16(&s->g);
+ bytestream2_skip(&s->g, 4);
+ bits_per_plane = bytestream2_peek_byte(&s->g) & 0xF;
+ s->nb_planes = (bytestream2_get_byte(&s->g) >> 4) + 1;
+ bpp = s->nb_planes ? bits_per_plane*s->nb_planes :
bits_per_plane;
if (bits_per_plane > 8 || bpp < 1 || bpp > 32) {
av_log_ask_for_sample(s, "unsupported bit depth\n");
return AVERROR_INVALIDDATA;
}
- if (*buf == 0xFF) {
- buf += 2;
- etype = bytestream_get_le16(&buf);
- esize = bytestream_get_le16(&buf);
- if (buf_end - buf < esize)
+ if (bytestream2_peek_byte(&s->g) == 0xFF) {
+ bytestream2_skip(&s->g, 2);
+ etype = bytestream2_get_le16(&s->g);
+ esize = bytestream2_get_le16(&s->g);
+ if (bytestream2_get_bytes_left(&s->g) < esize)
return AVERROR_INVALIDDATA;
} else {
etype = -1;
@@ -151,24 +151,31 @@ static int decode_frame(AVCodecContext *avctx,
s->frame.pict_type = AV_PICTURE_TYPE_I;
s->frame.palette_has_changed = 1;
+ pos_after_pal = bytestream2_tell(&s->g) + esize;
palette = (uint32_t*)s->frame.data[1];
- if (etype == 1 && esize > 1 && *buf < 6) {
- int idx = *buf;
+ if (etype == 1 && esize > 1 && bytestream2_peek_byte(&s->g) < 6) {
+ int idx = bytestream2_peek_byte(&s->g);
npal = 4;
for (i = 0; i < npal; i++)
palette[i] = ff_cga_palette[ cga_mode45_index[idx][i] ];
} else if (etype == 2) {
npal = FFMIN(esize, 16);
- for (i = 0; i < npal; i++)
- palette[i] = ff_cga_palette[ FFMIN(buf[i], 16)];
+ for (i = 0; i < npal; i++) {
+ int tmp;
+ tmp = bytestream2_get_byte(&s->g);
+ palette[i] = ff_cga_palette[ FFMIN(tmp, 16)];
+ }
} else if (etype == 3) {
npal = FFMIN(esize, 16);
- for (i = 0; i < npal; i++)
- palette[i] = ff_ega_palette[ FFMIN(buf[i], 63)];
+ for (i = 0; i < npal; i++) {
+ int tmp;
+ tmp = bytestream2_get_byte(&s->g);
+ palette[i] = ff_ega_palette[ FFMIN(tmp, 63)];
+ }
} else if (etype == 4 || etype == 5) {
npal = FFMIN(esize / 3, 256);
for (i = 0; i < npal; i++)
- palette[i] = AV_RB24(buf + i*3) << 2;
+ palette[i] = bytestream2_get_be24(&s->g) << 2;
} else {
if (bpp == 1) {
npal = 2;
@@ -185,29 +192,37 @@ static int decode_frame(AVCodecContext *avctx,
}
// fill remaining palette entries
memset(palette + npal, 0, AVPALETTE_SIZE - npal * 4);
- buf += esize;
-
+ // skip remaining palette bytes
+ bytestream2_seek(&s->g, pos_after_pal, SEEK_SET);
x = 0;
y = s->height - 1;
plane = 0;
- if (bytestream_get_le16(&buf)) {
- while (buf_end - buf >= 6) {
- const uint8_t *buf_pend = buf + FFMIN(AV_RL16(buf), buf_end - buf);
- //ignore uncompressed block size reported at buf[2]
- int marker = buf[4];
- buf += 5;
-
- while (plane < s->nb_planes && buf_pend - buf >= 1) {
+ if (bytestream2_get_le16(&s->g)) {
+ while (bytestream2_get_bytes_left(&s->g) >= 6) {
+ int bytes_left, marker, t1, t2;
+
+ t1 = bytestream2_get_bytes_left(&s->g);
+ t2 = bytestream2_get_le16(&s->g);
+ bytes_left = FFMIN(t1, t2);
+ bytestream2_skip(&s->g, 2); //ignore uncompressed block size
reported at buf[2]
+ marker = bytestream2_get_byte(&s->g);
+ bytes_left -= 5;
+
+ while (plane < s->nb_planes && bytes_left > 0) {
int run = 1;
- int val = *buf++;
+ int val = bytestream2_get_byte(&s->g);
+ bytes_left--;
if (val == marker) {
- run = *buf++;
- if (run == 0)
- run = bytestream_get_le16(&buf);
- val = *buf++;
+ run = bytestream2_get_byte(&s->g);
+ if (run == 0) {
+ run = bytestream2_get_le16(&s->g);
+ bytes_left -= 2;
+ }
+ val = bytestream2_get_byte(&s->g);
+ bytes_left -= 2;
}
- if (buf > buf_end)
+ if (!bytestream2_get_bytes_left(&s->g))
break;
if (bits_per_plane == 8) {
@@ -221,12 +236,12 @@ static int decode_frame(AVCodecContext *avctx,
}
} else {
av_log_ask_for_sample(s, "uncompressed image\n");
- return buf_size;
+ return avpkt->size;
}
*data_size = sizeof(AVFrame);
*(AVFrame*)data = s->frame;
- return buf_size;
+ return avpkt->size;
}
static av_cold int decode_end(AVCodecContext *avctx)
--
1.7.5.4
_______________________________________________
libav-devel mailing list
[email protected]
https://lists.libav.org/mailman/listinfo/libav-devel
