[FFmpeg-cvslog] avcodec/gdv: add decompression for 2 and 5 method
Paul B Mahol
git at videolan.org
Thu Jun 29 16:59:33 EEST 2017
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Wed Jun 28 19:24:29 2017 +0200| [4d681269e0966446b21a324c15c5e5e6cef7c378] | committer: Paul B Mahol
avcodec/gdv: add decompression for 2 and 5 method
Signed-off-by: Paul B Mahol <onemda at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=4d681269e0966446b21a324c15c5e5e6cef7c378
---
libavcodec/gdv.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
libavformat/gdv.c | 44 ++++++++++++++++++++--
2 files changed, 148 insertions(+), 3 deletions(-)
diff --git a/libavcodec/gdv.c b/libavcodec/gdv.c
index 275af9a351..b324e4f26e 100644
--- a/libavcodec/gdv.c
+++ b/libavcodec/gdv.c
@@ -38,6 +38,11 @@ typedef struct GDVContext {
unsigned scale_h, scale_v;
} GDVContext;
+typedef struct Bits8 {
+ uint8_t queue;
+ uint8_t fill;
+} Bits8;
+
typedef struct Bits32 {
uint32_t queue;
uint8_t fill;
@@ -124,6 +129,21 @@ static void rescale(GDVContext *gdv, uint8_t *dst, int w, int h, int scale_v, in
gdv->scale_h = scale_h;
}
+static int read_bits2(Bits8 *bits, GetByteContext *gb)
+{
+ int res;
+
+ if (bits->fill == 0) {
+ bits->queue |= bytestream2_get_byte(gb);
+ bits->fill = 8;
+ }
+ res = bits->queue >> 6;
+ bits->queue <<= 2;
+ bits->fill -= 2;
+
+ return res;
+}
+
static void fill_bits32(Bits32 *bits, GetByteContext *gb)
{
bits->queue = bytestream2_get_le32(gb);
@@ -173,6 +193,87 @@ static void lz_copy(PutByteContext *pb, GetByteContext *g2, int offset, unsigned
}
}
+static int decompress_2(AVCodecContext *avctx)
+{
+ GDVContext *gdv = avctx->priv_data;
+ GetByteContext *gb = &gdv->gb;
+ GetByteContext *g2 = &gdv->g2;
+ PutByteContext *pb = &gdv->pb;
+ Bits8 bits = { 0 };
+ int c, i;
+
+ bytestream2_init(g2, gdv->frame, gdv->frame_size);
+ bytestream2_skip_p(pb, PREAMBLE_SIZE);
+
+ for (c = 0; c < 256; c++) {
+ for (i = 0; i < 16; i++) {
+ gdv->frame[c * 16 + i] = c;
+ }
+ }
+
+ while (bytestream2_get_bytes_left_p(pb) > 0 && bytestream2_get_bytes_left(gb) > 0) {
+ int tag = read_bits2(&bits, gb);
+ if (tag == 0) {
+ bytestream2_put_byte(pb, bytestream2_get_byte(gb));
+ } else if (tag == 1) {
+ int b = bytestream2_get_byte(gb);
+ int len = (b & 0xF) + 3;
+ int top = (b >> 4) & 0xF;
+ int off = (bytestream2_get_byte(gb) << 4) + top - 4096;
+ lz_copy(pb, g2, off, len);
+ } else if (tag == 2) {
+ int len = (bytestream2_get_byte(gb)) + 2;
+ bytestream2_skip_p(pb, len);
+ } else {
+ break;
+ }
+ }
+ return 0;
+}
+
+static int decompress_5(AVCodecContext *avctx, unsigned skip)
+{
+ GDVContext *gdv = avctx->priv_data;
+ GetByteContext *gb = &gdv->gb;
+ GetByteContext *g2 = &gdv->g2;
+ PutByteContext *pb = &gdv->pb;
+ Bits8 bits = { 0 };
+
+ bytestream2_init(g2, gdv->frame, gdv->frame_size);
+ bytestream2_skip_p(pb, skip + PREAMBLE_SIZE);
+
+ while (bytestream2_get_bytes_left_p(pb) > 0 && bytestream2_get_bytes_left(gb) > 0) {
+ int tag = read_bits2(&bits, gb);
+ if (tag == 0) {
+ bytestream2_put_byte(pb, bytestream2_get_byte(gb));
+ } else if (tag == 1) {
+ int b = bytestream2_get_byte(gb);
+ int len = (b & 0xF) + 3;
+ int top = b >> 4;
+ int off = (bytestream2_get_byte(gb) << 4) + top - 4096;
+ lz_copy(pb, g2, off, len);
+ } else if (tag == 2) {
+ int len;
+ int b = bytestream2_get_byte(gb);
+ if (b == 0) {
+ break;
+ }
+ if (b != 0xFF) {
+ len = b;
+ } else {
+ len = bytestream2_get_le16(gb);
+ }
+ bytestream2_skip_p(pb, len + 1);
+ } else {
+ int b = bytestream2_get_byte(gb);
+ int len = (b & 0x3) + 2;
+ int off = -(b >> 2) - 1;
+ lz_copy(pb, g2, off, len);
+ }
+ }
+ return 0;
+}
+
static int decompress_68(AVCodecContext *avctx, unsigned skip, unsigned use8)
{
GDVContext *gdv = avctx->priv_data;
@@ -333,8 +434,14 @@ static int gdv_decode_frame(AVCodecContext *avctx, void *data,
gdv->pal[i] = 0xFFU << 24 | r << 18 | g << 10 | b << 2;
}
break;
+ case 2:
+ ret = decompress_2(avctx);
+ break;
case 3:
break;
+ case 5:
+ ret = decompress_5(avctx, flags >> 8);
+ break;
case 6:
ret = decompress_68(avctx, flags >> 8, 0);
break;
diff --git a/libavformat/gdv.c b/libavformat/gdv.c
index 87bba2fdbd..90692bd61c 100644
--- a/libavformat/gdv.c
+++ b/libavformat/gdv.c
@@ -42,14 +42,40 @@ static int gdv_read_probe(AVProbeData *p)
return 0;
}
+struct {
+ uint16_t id;
+ uint16_t width;
+ uint16_t height;
+} FixedSize[] = {
+ { 0, 320, 200},
+ { 1, 640, 200},
+ { 2, 320, 167},
+ { 3, 320, 180},
+ { 4, 320, 400},
+ { 5, 320, 170},
+ { 6, 160, 85},
+ { 7, 160, 83},
+ { 8, 160, 90},
+ { 9, 280, 128},
+ {10, 320, 240},
+ {11, 320, 201},
+ {16, 640, 400},
+ {17, 640, 200},
+ {18, 640, 180},
+ {19, 640, 167},
+ {20, 640, 170},
+ {21, 320, 240}
+};
+
static int gdv_read_header(AVFormatContext *ctx)
{
GDVContext *gdv = ctx->priv_data;
AVIOContext *pb = ctx->pb;
AVStream *vst, *ast;
- unsigned fps, snd_flags, vid_depth;
+ unsigned fps, snd_flags, vid_depth, size_id;
- avio_skip(pb, 6);
+ avio_skip(pb, 4);
+ size_id = avio_rl16(pb);
vst = avformat_new_stream(ctx, 0);
if (!vst)
@@ -91,6 +117,18 @@ static int gdv_read_header(AVFormatContext *ctx)
vst->codecpar->width = avio_rl16(pb);
vst->codecpar->height = avio_rl16(pb);
+ if (vst->codecpar->width == 0 || vst->codecpar->height == 0) {
+ int i;
+
+ for (i = 0; i < FF_ARRAY_ELEMS(FixedSize) - 1; i++) {
+ if (FixedSize[i].id == size_id)
+ break;
+ }
+
+ vst->codecpar->width = FixedSize[i].width;
+ vst->codecpar->height = FixedSize[i].height;
+ }
+
avpriv_set_pts_info(vst, 64, 1, fps);
if (vid_depth & 1) {
@@ -100,7 +138,7 @@ static int gdv_read_header(AVFormatContext *ctx)
unsigned r = avio_r8(pb);
unsigned g = avio_r8(pb);
unsigned b = avio_r8(pb);
- gdv->pal[i] = 0xFF << 24 | r << 18 | g << 10 | b << 2;
+ gdv->pal[i] = 0xFFU << 24 | r << 18 | g << 10 | b << 2;
}
}
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