#include "libavutil/intreadwrite.h"
#include "avcodec.h"
+#include "bytestream.h"
#define MM_PREAMBLE_SIZE 6
AVCodecContext *avctx;
AVFrame frame;
int palette[AVPALETTE_COUNT];
+ GetByteContext gb;
} MmContext;
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] = 0xFF << 24 | AV_RB24(buf);
+
+ bytestream2_skip(&s->gb, 4);
+ for (i = 0; i < 128; i++) {
+ s->palette[i] = 0xFF << 24 | 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;
+ int x, y;
+ 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)
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)
{
- int data_ptr;
- int d, r, y;
+ int data_off = bytestream2_get_le16(&s->gb), y = 0;
+ GetByteContext data_ptr;
- if(buf_size < 2) {
- av_log(s->avctx, AV_LOG_ERROR, "1 or less byte inter frame\n");
- return;
- }
+ if (bytestream2_get_bytes_left(&s->gb) < data_off)
+ return AVERROR_INVALIDDATA;
- data_ptr = 2 + AV_RL16(&buf[0]);
- d = data_ptr; r = 2; y = 0;
-
- while(r + 1 < data_ptr) {
+ 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;
continue;
}
- if (y + half_vert >= s->avctx->height || r+length > buf_size)
- return;
+ if (y + half_vert >= s->avctx->height)
+ 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;
- if (d >= buf_size) {
- av_log(s->avctx, AV_LOG_ERROR, "overread buf\n");
- return;
- }
- 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;
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,
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");
}
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);
.close = mm_decode_end,
.decode = mm_decode_frame,
.capabilities = CODEC_CAP_DR1,
- .long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM Video"),
+ .long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM Video"),
};