[FFmpeg-cvslog] algmm: convert to bytestream2 API.
Ronald S. Bultje
git at videolan.org
Thu Mar 8 03:10:34 CET 2012
ffmpeg | branch: master | Ronald S. Bultje <rsbultje at gmail.com> | Tue Mar 6 15:15:42 2012 -0800| [a55d5bdc6e28a2cfefc440d792de5cc4f02377e2] | committer: Ronald S. Bultje
algmm: convert to bytestream2 API.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable at libav.org
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a55d5bdc6e28a2cfefc440d792de5cc4f02377e2
---
libavcodec/mmvideo.c | 89 ++++++++++++++++++++++++++++---------------------
1 files changed, 51 insertions(+), 38 deletions(-)
diff --git a/libavcodec/mmvideo.c b/libavcodec/mmvideo.c
index 9e82ef9..501371a 100644
--- a/libavcodec/mmvideo.c
+++ b/libavcodec/mmvideo.c
@@ -33,6 +33,7 @@
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
+#include "bytestream.h"
#define MM_PREAMBLE_SIZE 6
@@ -48,6 +49,7 @@ typedef struct MmContext {
AVCodecContext *avctx;
AVFrame frame;
int palette[AVPALETTE_COUNT];
+ GetByteContext gb;
} MmContext;
static av_cold int mm_decode_init(AVCodecContext *avctx)
@@ -63,40 +65,40 @@ static av_cold int mm_decode_init(AVCodecContext *avctx)
return 0;
}
-static void mm_decode_pal(MmContext *s, const uint8_t *buf, const uint8_t *buf_end)
+static int mm_decode_pal(MmContext *s)
{
int i;
- buf += 4;
- for (i=0; i<128 && buf+2<buf_end; i++) {
- s->palette[i] = AV_RB24(buf);
+
+ bytestream2_skip(&s->gb, 4);
+ for (i = 0; i < 128; i++) {
+ s->palette[i] = bytestream2_get_be24(&s->gb);
s->palette[i+128] = s->palette[i]<<2;
- buf += 3;
}
+
+ return 0;
}
/**
* @param half_horiz Half horizontal resolution (0 or 1)
* @param half_vert Half vertical resolution (0 or 1)
*/
-static void mm_decode_intra(MmContext * s, int half_horiz, int half_vert, const uint8_t *buf, int buf_size)
+static int mm_decode_intra(MmContext * s, int half_horiz, int half_vert)
{
int i, x, y;
i=0; x=0; y=0;
- while(i<buf_size) {
+ while (bytestream2_get_bytes_left(&s->gb) > 0) {
int run_length, color;
if (y >= s->avctx->height)
- return;
+ return 0;
- if (buf[i] & 0x80) {
+ color = bytestream2_get_byte(&s->gb);
+ if (color & 0x80) {
run_length = 1;
- color = buf[i];
- i++;
}else{
- run_length = (buf[i] & 0x7f) + 2;
- color = buf[i+1];
- i+=2;
+ run_length = (color & 0x7f) + 2;
+ color = bytestream2_get_byte(&s->gb);
}
if (half_horiz)
@@ -114,23 +116,28 @@ static void mm_decode_intra(MmContext * s, int half_horiz, int half_vert, const
y += 1 + half_vert;
}
}
+
+ return 0;
}
/*
* @param half_horiz Half horizontal resolution (0 or 1)
* @param half_vert Half vertical resolution (0 or 1)
*/
-static void mm_decode_inter(MmContext * s, int half_horiz, int half_vert, const uint8_t *buf, int buf_size)
+static int mm_decode_inter(MmContext * s, int half_horiz, int half_vert)
{
- const int data_ptr = 2 + AV_RL16(&buf[0]);
- int d, r, y;
- d = data_ptr; r = 2; y = 0;
+ int data_off = bytestream2_get_le16(&s->gb), y;
+ GetByteContext data_ptr;
- while(r < data_ptr) {
+ if (bytestream2_get_bytes_left(&s->gb) < data_off)
+ return AVERROR_INVALIDDATA;
+
+ bytestream2_init(&data_ptr, s->gb.buffer + data_off, bytestream2_get_bytes_left(&s->gb) - data_off);
+ while (s->gb.buffer < data_ptr.buffer_start) {
int i, j;
- int length = buf[r] & 0x7f;
- int x = buf[r+1] + ((buf[r] & 0x80) << 1);
- r += 2;
+ int length = bytestream2_get_byte(&s->gb);
+ int x = bytestream2_get_byte(&s->gb) + ((length & 0x80) << 1);
+ length &= 0x7F;
if (length==0) {
y += x;
@@ -138,13 +145,14 @@ static void mm_decode_inter(MmContext * s, int half_horiz, int half_vert, const
}
if (y + half_vert >= s->avctx->height)
- return;
+ return 0;
for(i=0; i<length; i++) {
+ int replace_array = bytestream2_get_byte(&s->gb);
for(j=0; j<8; j++) {
- int replace = (buf[r+i] >> (7-j)) & 1;
+ int replace = (replace_array >> (7-j)) & 1;
if (replace) {
- int color = buf[d];
+ int color = bytestream2_get_byte(&data_ptr);
s->frame.data[0][y*s->frame.linesize[0] + x] = color;
if (half_horiz)
s->frame.data[0][y*s->frame.linesize[0] + x + 1] = color;
@@ -153,15 +161,15 @@ static void mm_decode_inter(MmContext * s, int half_horiz, int half_vert, const
if (half_horiz)
s->frame.data[0][(y+1)*s->frame.linesize[0] + x + 1] = color;
}
- d++;
}
x += 1 + half_horiz;
}
}
- r += length;
y += 1 + half_vert;
}
+
+ return 0;
}
static int mm_decode_frame(AVCodecContext *avctx,
@@ -171,12 +179,14 @@ static int mm_decode_frame(AVCodecContext *avctx,
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
MmContext *s = avctx->priv_data;
- const uint8_t *buf_end = buf+buf_size;
- int type;
+ int type, res;
+ if (buf_size < MM_PREAMBLE_SIZE)
+ return AVERROR_INVALIDDATA;
type = AV_RL16(&buf[0]);
buf += MM_PREAMBLE_SIZE;
buf_size -= MM_PREAMBLE_SIZE;
+ bytestream2_init(&s->gb, buf, buf_size);
if (avctx->reget_buffer(avctx, &s->frame) < 0) {
av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
@@ -184,16 +194,19 @@ static int mm_decode_frame(AVCodecContext *avctx,
}
switch(type) {
- case MM_TYPE_PALETTE : mm_decode_pal(s, buf, buf_end); return buf_size;
- case MM_TYPE_INTRA : mm_decode_intra(s, 0, 0, buf, buf_size); break;
- case MM_TYPE_INTRA_HH : mm_decode_intra(s, 1, 0, buf, buf_size); break;
- case MM_TYPE_INTRA_HHV : mm_decode_intra(s, 1, 1, buf, buf_size); break;
- case MM_TYPE_INTER : mm_decode_inter(s, 0, 0, buf, buf_size); break;
- case MM_TYPE_INTER_HH : mm_decode_inter(s, 1, 0, buf, buf_size); break;
- case MM_TYPE_INTER_HHV : mm_decode_inter(s, 1, 1, buf, buf_size); break;
- default :
- return -1;
+ case MM_TYPE_PALETTE : res = mm_decode_pal(s); return buf_size;
+ case MM_TYPE_INTRA : res = mm_decode_intra(s, 0, 0); break;
+ case MM_TYPE_INTRA_HH : res = mm_decode_intra(s, 1, 0); break;
+ case MM_TYPE_INTRA_HHV : res = mm_decode_intra(s, 1, 1); break;
+ case MM_TYPE_INTER : res = mm_decode_inter(s, 0, 0); break;
+ case MM_TYPE_INTER_HH : res = mm_decode_inter(s, 1, 0); break;
+ case MM_TYPE_INTER_HHV : res = mm_decode_inter(s, 1, 1); break;
+ default:
+ res = AVERROR_INVALIDDATA;
+ break;
}
+ if (res < 0)
+ return res;
memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
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