[FFmpeg-devel] [PATCH 2/3] avcodec: add Gremlin Digital Video decoder
Paul B Mahol
onemda at gmail.com
Fri Jun 2 22:56:18 EEST 2017
Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 1 +
libavcodec/avcodec.h | 1 +
libavcodec/codec_desc.c | 7 +
libavcodec/gdv.c | 404 ++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 414 insertions(+)
create mode 100644 libavcodec/gdv.c
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 759cc0c..af24ecd 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -308,6 +308,7 @@ OBJS-$(CONFIG_G723_1_DECODER) += g723_1dec.o g723_1.o \
OBJS-$(CONFIG_G723_1_ENCODER) += g723_1enc.o g723_1.o \
acelp_vectors.o celp_filters.o celp_math.o
OBJS-$(CONFIG_G729_DECODER) += g729dec.o lsp.o celp_math.o celp_filters.o acelp_filters.o acelp_pitch_delay.o acelp_vectors.o g729postfilter.o
+OBJS-$(CONFIG_GDV_DECODER) += gdv.o
OBJS-$(CONFIG_GIF_DECODER) += gifdec.o lzw.o
OBJS-$(CONFIG_GIF_ENCODER) += gif.o lzwenc.o
OBJS-$(CONFIG_GREMLIN_DPCM_DECODER) += dpcm.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 31a6010..a1046d0 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -194,6 +194,7 @@ static void register_all(void)
REGISTER_DECODER(FRAPS, fraps);
REGISTER_DECODER(FRWU, frwu);
REGISTER_DECODER(G2M, g2m);
+ REGISTER_DECODER(GDV, gdv);
REGISTER_ENCDEC (GIF, gif);
REGISTER_ENCDEC (H261, h261);
REGISTER_ENCDEC (H263, h263);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 59bd1c5..dcdcfe0 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -446,6 +446,7 @@ enum AVCodecID {
AV_CODEC_ID_MSCC,
AV_CODEC_ID_SRGC,
AV_CODEC_ID_SVG,
+ AV_CODEC_ID_GDV,
/* various PCM "codecs" */
AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index 4cc5729..cf1246e 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1410,6 +1410,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
.long_name = NULL_IF_CONFIG_SMALL("Screen Recorder Gold Codec"),
.props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSLESS,
},
+ {
+ .id = AV_CODEC_ID_GDV,
+ .type = AVMEDIA_TYPE_VIDEO,
+ .name = "gdv",
+ .long_name = NULL_IF_CONFIG_SMALL("Gremlin Digital Video"),
+ .props = AV_CODEC_PROP_LOSSY,
+ },
/* image codecs */
{
diff --git a/libavcodec/gdv.c b/libavcodec/gdv.c
new file mode 100644
index 0000000..975031f
--- /dev/null
+++ b/libavcodec/gdv.c
@@ -0,0 +1,404 @@
+/*
+ * Grelmlin Digital Video (GDV) decoder
+ * Copyright (c) 2017 Konstantin Shishkov
+ * Copyright (c) 2017 Paul B Mahol
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/common.h"
+#include "avcodec.h"
+#include "bytestream.h"
+#include "internal.h"
+
+typedef struct GDVContext {
+ AVCodecContext *avctx;
+
+ GetByteContext gb;
+ GetByteContext g2;
+ PutByteContext pb;
+
+ uint32_t pal[256];
+ uint8_t *frame;
+ unsigned frame_size;
+ unsigned scale_h, scale_v;
+} GDVContext;
+
+typedef struct Bits32 {
+ uint32_t queue;
+ uint8_t fill;
+} Bits32;
+
+#define PREAMBLE_SIZE 4096
+
+static av_cold int gdv_decode_init(AVCodecContext *avctx)
+{
+ GDVContext *gdv = avctx->priv_data;
+ int i, j, k;
+
+ avctx->pix_fmt = AV_PIX_FMT_PAL8;
+ gdv->frame_size = avctx->width * avctx->height + PREAMBLE_SIZE;
+ gdv->frame = av_calloc(gdv->frame_size, 1);
+ if (!gdv->frame)
+ return AVERROR(ENOMEM);
+
+ for (i = 0; i < 2; i++) {
+ for (j = 0; j < 256; j++) {
+ for (k = 0; k < 8; k++) {
+ gdv->frame[i * 2048 + j * 8 + k] = j;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static void rescale(GDVContext *gdv, uint8_t *dst, int w, int h, int scale_v, int scale_h)
+{
+ int i, j, y, x;
+
+ if ((gdv->scale_v == scale_v) && (gdv->scale_h == scale_h)) {
+ return;
+ }
+
+ if (gdv->scale_h && gdv->scale_v) {
+ for (j = 0; j < h; j++) {
+ int y = h - j - 1;
+ for (i = 0; i < w; i++) {
+ int x = w - i - 1;
+ dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x/2 + (y/2) * (w/2)];
+ }
+ }
+ } else if (gdv->scale_h) {
+ for (j = 0; j < h; j++) {
+ int y = h - j - 1;
+ for (x = 0; x < w; x++) {
+ dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x + (y/2) * w];
+ }
+ }
+ } else if (gdv->scale_v) {
+ for (j = 0; j < h; j++) {
+ int y = h - j - 1;
+ for (i = 0; i < w; i++) {
+ int x = w - i - 1;
+ dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x/2 + y * (w/2)];
+ }
+ }
+ }
+
+ if (scale_h && scale_v) {
+ for (y = 0; y < h/2; y++) {
+ for (x = 0; x < w/2; x++) {
+ dst[PREAMBLE_SIZE + x + y * (w/2)] = dst[PREAMBLE_SIZE + x*2 + y*2 * w];
+ }
+ }
+ } else if (scale_h) {
+ for (y = 0; y < h/2; y++) {
+ for (x = 0; x < w; x++) {
+ dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x + y*2 * w];
+ }
+ }
+ } else if (scale_v) {
+ for (y = 0; y < h; y++) {
+ for (x = 0; x < w/2; x++) {
+ dst[PREAMBLE_SIZE + x + y * w] = dst[PREAMBLE_SIZE + x*2 + y * w];
+ }
+ }
+ }
+
+ gdv->scale_v = scale_v;
+ gdv->scale_h = scale_h;
+}
+
+static void fill_bits32(Bits32 *bits, GetByteContext *gb)
+{
+ bits->queue = bytestream2_get_le32(gb);
+ bits->fill = 32;
+}
+
+static int read_bits32(Bits32 *bits, GetByteContext *gb, int nbits)
+{
+ int res = bits->queue & ((1 << nbits) - 1);
+
+ bits->queue >>= nbits;
+ bits->fill -= nbits;
+ if (bits->fill <= 16) {
+ bits->queue |= bytestream2_get_le16(gb) << bits->fill;
+ bits->fill += 16;
+ }
+
+ return res;
+}
+
+static void lz_copy(PutByteContext *pb, GetByteContext *g2, int offset, unsigned len)
+{
+ int i;
+
+ if (offset == -1) {
+ int c;
+
+ bytestream2_seek(g2, bytestream2_tell_p(pb) - 1, SEEK_SET);
+ c = bytestream2_get_byte(g2);
+ for (i = 0; i < len; i++) {
+ bytestream2_put_byte(pb, c);
+ }
+ } else if (offset < 0) {
+ int start = bytestream2_tell_p(pb) - (-offset);
+
+ bytestream2_seek(g2, start, SEEK_SET);
+ for (i = 0; i < len; i++) {
+ bytestream2_put_byte(pb, bytestream2_get_byte(g2));
+ }
+ } else {
+ int start = bytestream2_tell_p(pb) + offset;
+
+ bytestream2_seek(g2, start, SEEK_SET);
+ for (i = 0; i < len; i++) {
+ bytestream2_put_byte(pb, bytestream2_get_byte(g2));
+ }
+ }
+}
+
+static int decompress_68(AVCodecContext *avctx, unsigned skip, unsigned use8)
+{
+ GDVContext *gdv = avctx->priv_data;
+ GetByteContext *gb = &gdv->gb;
+ GetByteContext *g2 = &gdv->g2;
+ PutByteContext *pb = &gdv->pb;
+ Bits32 bits;
+
+ bytestream2_init(g2, gdv->frame, gdv->frame_size);
+ bytestream2_skip_p(pb, skip + PREAMBLE_SIZE);
+ fill_bits32(&bits, gb);
+
+ while (bytestream2_get_bytes_left_p(pb) > 0 && bytestream2_get_bytes_left(gb) > 0) {
+ int tag = read_bits32(&bits, gb, 2);
+ if (tag == 0) {
+ int b = read_bits32(&bits, gb, 1);
+ if (b == 0) {
+ bytestream2_put_byte(pb, bytestream2_get_byte(gb));
+ } else {
+ int i, len = 2;
+ int lbits = 0;
+ while (1) {
+ int val;
+
+ lbits += 1;
+ val = read_bits32(&bits, gb, lbits);
+ len += val;
+ if (val != ((1 << lbits) - 1)) {
+ break;
+ }
+ assert(lbits < 16);
+ }
+ for (i = 0; i < len; i++) {
+ bytestream2_put_byte(pb, bytestream2_get_byte(gb));
+ }
+ }
+ } else if (tag == 1) {
+ int b = read_bits32(&bits, gb, 1);
+ int len;
+
+ if (b == 0) {
+ len = (read_bits32(&bits, gb, 4)) + 2;
+ } else {
+ int bb = bytestream2_get_byte(gb);
+ if ((bb & 0x80) == 0) {
+ len = bb + 18;
+ } else {
+ int top = (bb & 0x7F) << 8;
+ len = top + bytestream2_get_byte(gb) + 146;
+ }
+ }
+ bytestream2_skip_p(pb, len);
+ } else if (tag == 2) {
+ int i, subtag = read_bits32(&bits, gb, 2);
+
+ if (subtag != 3) {
+ int top = (read_bits32(&bits, gb, 4)) << 8;
+ int offs = top + bytestream2_get_byte(gb);
+ if ((subtag != 0) || (offs <= 0xF80)) {
+ int len = (subtag) + 3;
+ lz_copy(pb, g2, (offs) - 4096, len);
+ } else {
+ if (offs == 0xFFF) {
+ return 0;
+ }
+
+ int real_off = ((offs >> 4) & 0x7) + 1;
+ int len = ((offs & 0xF) + 2) * 2;
+ int c1 = gdv->frame[bytestream2_tell_p(pb) - real_off];
+ int c2 = gdv->frame[bytestream2_tell_p(pb) - real_off + 1];
+ for (i = 0; i < len/2; i++) {
+ bytestream2_put_byte(pb, c1);
+ bytestream2_put_byte(pb, c2);
+ }
+ }
+ } else {
+ int b = bytestream2_get_byte(gb);
+ int off = ((b & 0x7F)) + 1;
+ int len = ((b & 0x80) == 0) ? 2 : 3;
+
+ lz_copy(pb, g2, -off, len);
+ }
+ } else {
+ int len;
+ int off;
+ if (use8) {
+ int b = bytestream2_get_byte(gb);
+ if ((b & 0xC0) == 0xC0) {
+ len = ((b & 0x3F)) + 8;
+ int q = read_bits32(&bits, gb, 4);
+ off = (q << 8) + (bytestream2_get_byte(gb)) + 1;
+ } else {
+ int ofs1;
+ if ((b & 0x80) == 0) {
+ len = ((b >> 4)) + 6;
+ ofs1 = (b & 0xF);
+ } else {
+ len = ((b & 0x3F)) + 14;
+ ofs1 = read_bits32(&bits, gb, 4);
+ }
+ off = (ofs1 << 8) + (bytestream2_get_byte(gb)) - 4096;
+ }
+ } else {
+ int b = bytestream2_get_byte(gb);
+
+ if ((b >> 4) == 0xF) {
+ len = bytestream2_get_byte(gb) + 21;
+ } else {
+ len = (b >> 4) + 6;
+ }
+ int ofs1 = (b & 0xF);
+ off = (ofs1 << 8) + bytestream2_get_byte(gb) - 4096;
+ }
+ lz_copy(pb, g2, off, len);
+ }
+ }
+
+ return 0;
+}
+
+static int gdv_decode_frame(AVCodecContext *avctx, void *data,
+ int *got_frame, AVPacket *avpkt)
+{
+ GDVContext *gdv = avctx->priv_data;
+ GetByteContext *gb = &gdv->gb;
+ PutByteContext *pb = &gdv->pb;
+ AVFrame *frame = data;
+ int ret, i, pal_size;
+ const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &pal_size);
+ int compression;
+ unsigned flags;
+ uint8_t *dst;
+
+ if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+ return ret;
+ if (pal && pal_size == AVPALETTE_SIZE)
+ memcpy(gdv->pal, pal, AVPALETTE_SIZE);
+
+ bytestream2_init(gb, avpkt->data, avpkt->size);
+ bytestream2_init_writer(pb, gdv->frame, gdv->frame_size);
+
+ flags = bytestream2_get_le32(gb);
+ compression = flags & 0xF;
+
+ rescale(gdv, gdv->frame, avctx->width, avctx->height,
+ !!(flags & 0x10), !!(flags & 0x20));
+
+ switch (compression) {
+ case 1:
+ memset(gdv->frame + PREAMBLE_SIZE, 0, gdv->frame_size - PREAMBLE_SIZE);
+ case 0:
+ for (i = 0; i < 256; i++) {
+ unsigned r = bytestream2_get_byte(gb);
+ unsigned g = bytestream2_get_byte(gb);
+ unsigned b = bytestream2_get_byte(gb);
+ gdv->pal[i] = 0xFF << 24 | r << 18 | g << 10 | b << 2;
+ }
+ break;
+ case 3:
+ break;
+ case 6:
+ ret = decompress_68(avctx, flags >> 8, 0);
+ break;
+ case 8:
+ ret = decompress_68(avctx, flags >> 8, 1);
+ break;
+ default:
+ return AVERROR_INVALIDDATA;
+ }
+
+ memcpy(frame->data[1], gdv->pal, AVPALETTE_SIZE);
+ dst = frame->data[0];
+
+ if (!gdv->scale_v && !gdv->scale_h) {
+ int sidx = PREAMBLE_SIZE, didx = 0;
+ int y, x;
+
+ for (y = 0; y < avctx->height; y++) {
+ for (x = 0; x < avctx->width; x++) {
+ dst[x+didx] = gdv->frame[x+sidx];
+ }
+ sidx += avctx->width;
+ didx += frame->linesize[0];
+ }
+ } else {
+ int sidx = PREAMBLE_SIZE, didx = 0;
+ int y, x;
+
+ for (y = 0; y < avctx->height; y++) {
+ if (!gdv->scale_v) {
+ for (x = 0; x < avctx->width; x++) {
+ dst[didx + x] = gdv->frame[sidx + x];
+ }
+ } else {
+ for (x = 0; x < avctx->width; x++) {
+ dst[didx + x] = gdv->frame[sidx + x/2];
+ }
+ }
+ if (!gdv->scale_h || ((y & 1) == 1)) {
+ sidx += !gdv->scale_v ? avctx->width : avctx->width/2;
+ }
+ didx += frame->linesize[0];
+ }
+ }
+
+ *got_frame = 1;
+
+ return ret < 0 ? ret : avpkt->size;
+}
+
+static av_cold int gdv_decode_close(AVCodecContext *avctx)
+{
+ GDVContext *gdv = avctx->priv_data;
+ av_freep(&gdv->frame);
+ return 0;
+}
+
+AVCodec ff_gdv_decoder = {
+ .name = "gdv",
+ .long_name = NULL_IF_CONFIG_SMALL("Gremlin Digital Video"),
+ .type = AVMEDIA_TYPE_VIDEO,
+ .id = AV_CODEC_ID_GDV,
+ .priv_data_size = sizeof(GDVContext),
+ .init = gdv_decode_init,
+ .close = gdv_decode_close,
+ .decode = gdv_decode_frame,
+ .capabilities = AV_CODEC_CAP_DR1,
+ .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
+};
--
2.9.3
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