Canopus Lossless decoder

At the moment it only does BGR24, but I plan to add the rest after.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

1 files changed, 284 insertions, 0 deletions

diff --git a/libavcodec/cllc.c b/libavcodec/cllc.c
new file mode 100644
index 0000000000..aca4669fcb
--- /dev/null
+++ b/libavcodec/cllc.c
@@ -0,0 +1,284 @@
+/*
+ * Canopus Lossless Codec decoder
+ *
+ * Copyright (c) 2012 Derek Buitenhuis
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "dsputil.h"
+#include "get_bits.h"
+#include "avcodec.h"
+
+typedef struct CLLCContext {
+    DSPContext dsp;
+    AVCodecContext *avctx;
+
+    uint8_t *swapped_buf;
+    int      swapped_buf_size;
+} CLLCContext;
+
+static int read_code_table(CLLCContext *ctx, GetBitContext *gb, VLC *vlc)
+{
+    uint8_t symbols[256];
+    uint8_t bits[256];
+    uint16_t codes[256];
+    int num_lens, num_codes, num_codes_sum, prefix;
+    int i, j, count;
+
+    prefix        = 0;
+    count         = 0;
+    num_codes_sum = 0;
+
+    num_lens = get_bits(gb, 5);
+
+    for (i = 0; i < num_lens; i++) {
+        num_codes      = get_bits(gb, 9);
+        num_codes_sum += num_codes;
+
+        if (num_codes_sum > 256) {
+            vlc->table = NULL;
+
+            av_log(ctx->avctx, AV_LOG_ERROR,
+                   "Too many VLCs (%d) to be read.\n", num_codes_sum);
+            return AVERROR_INVALIDDATA;
+        }
+
+        for (j = 0; j < num_codes; j++) {
+            symbols[count] = get_bits(gb, 8);
+            bits[count]    = i + 1;
+            codes[count]   = prefix++;
+
+            count++;
+        }
+
+        prefix <<= 1;
+    }
+
+    return ff_init_vlc_sparse(vlc, 7, count, bits, 1, 1,
+                              codes, 2, 2, symbols, 1, 1, 0);
+}
+
+static int read_line(CLLCContext *ctx, GetBitContext *gb, int *top_left,
+                     VLC *vlc, uint8_t *outbuf)
+{
+    uint8_t *dst;
+    int pred, code;
+    int i;
+
+    OPEN_READER(bits, gb);
+
+    dst  = outbuf;
+    pred = *top_left;
+
+    /* Simultaneously read and restore the line */
+    for (i = 0; i < ctx->avctx->width; i++) {
+        UPDATE_CACHE(bits, gb);
+        GET_VLC(code, bits, gb, vlc->table, 7, 2);
+
+        pred  += code;
+        dst[0] = pred;
+        dst   += 3;
+    }
+
+    CLOSE_READER(bits, gb);
+
+    /* Stash the first pixel */
+    *top_left = dst[-3 * ctx->avctx->width];
+
+    return 0;
+}
+
+static int decode_bgr24_frame(CLLCContext *ctx, GetBitContext *gb, AVFrame *pic)
+{
+    AVCodecContext *avctx = ctx->avctx;
+    uint8_t *dst;
+    int pred[3];
+    int ret;
+    int i, j;
+    VLC vlc[3];
+
+    pred[0] = 0x80;
+    pred[1] = 0x80;
+    pred[2] = 0x80;
+
+    dst = pic->data[0];
+
+    skip_bits(gb, 16);
+
+    /* Read in code table for each plane */
+    for (i = 0; i < 3; i++) {
+        ret = read_code_table(ctx, gb, &vlc[i]);
+        if (ret < 0) {
+            for (j = 0; j <= i; j++)
+                ff_free_vlc(&vlc[j]);
+
+            av_log(ctx->avctx, AV_LOG_ERROR,
+                   "Could not read code table %d.\n", i);
+            return ret;
+        }
+    }
+
+    /* Read in and restore every line */
+    for (i = 0; i < avctx->height; i++) {
+        for (j = 0; j < 3; j++)
+            read_line(ctx, gb, &pred[j], &vlc[j], &dst[j]);
+
+        dst += pic->linesize[0];
+    }
+
+    for (i = 0; i < 3; i++)
+        ff_free_vlc(&vlc[i]);
+
+    return 0;
+}
+
+static int cllc_decode_frame(AVCodecContext *avctx, void *data,
+                             int *got_picture_ptr, AVPacket *avpkt)
+{
+    CLLCContext *ctx = avctx->priv_data;
+    AVFrame *pic = avctx->coded_frame;
+    uint8_t *src = avpkt->data;
+    uint8_t *swapped_buf_new;
+    uint32_t info_tag, info_offset;
+    GetBitContext gb;
+    int coding_type, ret;
+
+    if (pic->data[0])
+        avctx->release_buffer(avctx, pic);
+
+    pic->reference = 0;
+
+    /* Make sure our bswap16'd buffer is big enough */
+    swapped_buf_new = av_fast_realloc(ctx->swapped_buf,
+                                      &ctx->swapped_buf_size, avpkt->size);
+    if (!swapped_buf_new) {
+        av_log(avctx, AV_LOG_ERROR, "Could not realloc swapped buffer.\n");
+        return AVERROR(ENOMEM);
+    }
+    ctx->swapped_buf = swapped_buf_new;
+
+    /* Skip the INFO header if present */
+    info_offset = 0;
+    info_tag    = AV_RL32(src);
+    if (info_tag == MKTAG('I', 'N', 'F', 'O')) {
+        info_offset = AV_RL32(src + 4);
+        if (info_offset > UINT32_MAX - 8 || info_offset + 8 > avpkt->size) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "Invalid INFO header offset: 0x%08X is too large.\n",
+                   info_offset);
+            return AVERROR_INVALIDDATA;
+        }
+
+        info_offset += 8;
+        src         += info_offset;
+
+        av_log(avctx, AV_LOG_DEBUG, "Skipping INFO chunk.\n");
+    }
+
+    /* bswap16 the buffer since CLLC's bitreader works in 16-bit words */
+    ctx->dsp.bswap16_buf((uint16_t *) ctx->swapped_buf, (uint16_t *) src,
+                         (avpkt->size - info_offset) / 2);
+
+    init_get_bits(&gb, ctx->swapped_buf, (avpkt->size - info_offset) * 8);
+
+    /*
+     * Read in coding type. The types are as follows:
+     *
+     * 0 - YUY2
+     * 1 - BGR24 (Triples)
+     * 2 - BGR24 (Quads)
+     * 3 - BGRA
+     */
+    coding_type = (AV_RL32(src) >> 8) & 0xFF;
+    av_log(avctx, AV_LOG_DEBUG, "Frame coding type: %d\n", coding_type);
+
+    switch (coding_type) {
+    case 1:
+        avctx->pix_fmt             = PIX_FMT_RGB24;
+        avctx->bits_per_raw_sample = 8;
+
+        ret = avctx->get_buffer(avctx, pic);
+        if (ret < 0) {
+            av_log(avctx, AV_LOG_ERROR, "Could not allocate buffer.\n");
+            return ret;
+        }
+
+        ret = decode_bgr24_frame(ctx, &gb, pic);
+        if (ret < 0)
+            return ret;
+
+        break;
+    default:
+        av_log(avctx, AV_LOG_ERROR, "Unknown coding type: %d\n.", coding_type);
+        return AVERROR_INVALIDDATA;
+    }
+
+    pic->key_frame = 1;
+    pic->pict_type = AV_PICTURE_TYPE_I;
+
+    *got_picture_ptr = 1;
+    *(AVFrame *)data = *pic;
+
+    return avpkt->size;
+}
+
+static av_cold int cllc_decode_close(AVCodecContext *avctx)
+{
+    CLLCContext *ctx = avctx->priv_data;
+
+    if (avctx->coded_frame->data[0])
+        avctx->release_buffer(avctx, avctx->coded_frame);
+
+    av_freep(&avctx->coded_frame);
+    av_freep(&ctx->swapped_buf);
+
+    return 0;
+}
+
+static av_cold int cllc_decode_init(AVCodecContext *avctx)
+{
+    CLLCContext *ctx = avctx->priv_data;
+
+    /* Initialize various context values */
+    ctx->avctx            = avctx;
+    ctx->swapped_buf      = NULL;
+    ctx->swapped_buf_size = 0;
+
+    ff_dsputil_init(&ctx->dsp, avctx);
+
+    avctx->coded_frame = avcodec_alloc_frame();
+    if (!avctx->coded_frame) {
+        av_log(avctx, AV_LOG_ERROR, "Could not allocate frame.\n");
+        return AVERROR(ENOMEM);
+    }
+
+    return 0;
+}
+
+AVCodec ff_cllc_decoder = {
+    .name           = "cllc",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_CLLC,
+    .priv_data_size = sizeof(CLLCContext),
+    .init           = cllc_decode_init,
+    .decode         = cllc_decode_frame,
+    .close          = cllc_decode_close,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("Canopus Lossless Codec"),
+};