Rename some variables and add some comments to try to be a bit more clear.

Originally committed as revision 15510 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Benoit Fouet 2008-10-02 15:27:13 +00:00
parent aaa0df02d3
commit 2c4b482931
1 changed files with 34 additions and 33 deletions

View File

@ -202,7 +202,7 @@ typedef struct {
static void iv_Decode_Chunk(Indeo3DecodeContext *s,
uint8_t *cur, uint8_t *ref, int width, int height,
const uint8_t *buf1, long fflags2, const uint8_t *hdr,
const uint8_t *buf1, long cb_offset, const uint8_t *hdr,
const uint8_t *buf2, int min_width_160)
{
uint8_t bit_buf;
@ -314,7 +314,7 @@ static void iv_Decode_Chunk(Indeo3DecodeContext *s,
k = *buf1 >> 4;
j = *buf1 & 0x0f;
buf1++;
lv = j + fflags2;
lv = j + cb_offset;
if((lv - 8) <= 7 && (k == 0 || k == 3 || k == 10)) {
cp2 = s->ModPred + ((lv - 8) << 7);
@ -326,10 +326,10 @@ static void iv_Decode_Chunk(Indeo3DecodeContext *s,
}
if(k == 1 || k == 4) {
lv = (hdr[j] & 0xf) + fflags2;
lv = (hdr[j] & 0xf) + cb_offset;
correction_type_sp[0] = s->corrector_type + (lv << 8);
correction_lp[0] = correction + (lv << 8);
lv = (hdr[j] >> 4) + fflags2;
lv = (hdr[j] >> 4) + cb_offset;
correction_lp[1] = correction + (lv << 8);
correction_type_sp[1] = s->corrector_type + (lv << 8);
} else {
@ -973,34 +973,35 @@ static av_cold int indeo3_decode_init(AVCodecContext *avctx)
static unsigned long iv_decode_frame(Indeo3DecodeContext *s,
const uint8_t *buf, int buf_size)
{
unsigned int hdr_width, hdr_height,
unsigned int image_width, image_height,
chroma_width, chroma_height;
unsigned long fflags1, fflags2, fflags3, offs1, offs2, offs3, offs;
unsigned long flags, cb_offset, data_size,
y_offset, v_offset, u_offset, mc_vector_count;
const uint8_t *hdr_pos, *buf_pos;
buf_pos = buf;
buf_pos += 18;
buf_pos += 18; /* skip OS header (16 bytes) and version number */
fflags1 = bytestream_get_le16(&buf_pos);
fflags3 = bytestream_get_le32(&buf_pos);
fflags2 = *buf_pos++;
buf_pos += 3;
hdr_height = bytestream_get_le16(&buf_pos);
hdr_width = bytestream_get_le16(&buf_pos);
flags = bytestream_get_le16(&buf_pos);
data_size = bytestream_get_le32(&buf_pos);
cb_offset = *buf_pos++;
buf_pos += 3; /* skip reserved byte and checksum */
image_height = bytestream_get_le16(&buf_pos);
image_width = bytestream_get_le16(&buf_pos);
if(avcodec_check_dimensions(NULL, hdr_width, hdr_height))
if(avcodec_check_dimensions(NULL, image_width, image_height))
return -1;
chroma_height = ((hdr_height >> 2) + 3) & 0x7ffc;
chroma_width = ((hdr_width >> 2) + 3) & 0x7ffc;
offs1 = bytestream_get_le32(&buf_pos);
offs2 = bytestream_get_le32(&buf_pos);
offs3 = bytestream_get_le32(&buf_pos);
buf_pos += 4;
chroma_height = ((image_height >> 2) + 3) & 0x7ffc;
chroma_width = ((image_width >> 2) + 3) & 0x7ffc;
y_offset = bytestream_get_le32(&buf_pos);
v_offset = bytestream_get_le32(&buf_pos);
u_offset = bytestream_get_le32(&buf_pos);
buf_pos += 4; /* reserved */
hdr_pos = buf_pos;
if(fflags3 == 0x80) return 4;
if(data_size == 0x80) return 4;
if(fflags1 & 0x200) {
if(flags & 0x200) {
s->cur_frame = s->iv_frame + 1;
s->ref_frame = s->iv_frame;
} else {
@ -1008,28 +1009,28 @@ static unsigned long iv_decode_frame(Indeo3DecodeContext *s,
s->ref_frame = s->iv_frame + 1;
}
buf_pos = buf + 16 + offs1;
offs = bytestream_get_le32(&buf_pos);
buf_pos = buf + 16 + y_offset;
mc_vector_count = bytestream_get_le32(&buf_pos);
iv_Decode_Chunk(s, s->cur_frame->Ybuf, s->ref_frame->Ybuf, hdr_width,
hdr_height, buf_pos + offs * 2, fflags2, hdr_pos, buf_pos,
FFMIN(hdr_width, 160));
iv_Decode_Chunk(s, s->cur_frame->Ybuf, s->ref_frame->Ybuf, image_width,
image_height, buf_pos + mc_vector_count * 2, cb_offset, hdr_pos, buf_pos,
FFMIN(image_width, 160));
if (!(s->avctx->flags & CODEC_FLAG_GRAY))
{
buf_pos = buf + 16 + offs2;
offs = bytestream_get_le32(&buf_pos);
buf_pos = buf + 16 + v_offset;
mc_vector_count = bytestream_get_le32(&buf_pos);
iv_Decode_Chunk(s, s->cur_frame->Vbuf, s->ref_frame->Vbuf, chroma_width,
chroma_height, buf_pos + offs * 2, fflags2, hdr_pos, buf_pos,
chroma_height, buf_pos + mc_vector_count * 2, cb_offset, hdr_pos, buf_pos,
FFMIN(chroma_width, 40));
buf_pos = buf + 16 + offs3;
offs = bytestream_get_le32(&buf_pos);
buf_pos = buf + 16 + u_offset;
mc_vector_count = bytestream_get_le32(&buf_pos);
iv_Decode_Chunk(s, s->cur_frame->Ubuf, s->ref_frame->Ubuf, chroma_width,
chroma_height, buf_pos + offs * 2, fflags2, hdr_pos, buf_pos,
chroma_height, buf_pos + mc_vector_count * 2, cb_offset, hdr_pos, buf_pos,
FFMIN(chroma_width, 40));
}