codec: bitpacked: add decoder

Add a codec capable of decoding some formats of the RFC4175. For now
it's only capable of handling YCbCr-4:2:2 with 8-bit or 10-bit depth.

For 8-bit it's a simple pass-through, for 10-bit it depacks the stream
in the AV_PIX_FMT_YUV422P10 pixel format.

Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com>
Reviewed-by: Rostislav Pehlivanov <atomnuker@gmail.com>

1 files changed, 153 insertions, 0 deletions

diff --git a/libavcodec/bitpacked.c b/libavcodec/bitpacked.c
new file mode 100644
index 0000000000..949d20c961
--- /dev/null
+++ b/libavcodec/bitpacked.c
@@ -0,0 +1,153 @@
+/*
+ * Unpack bit-packed streams to formats supported by FFmpeg
+ * Copyright (c) 2017 Savoir-faire Linux, Inc
+ *
+ * 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
+ */
+
+/* Development sponsored by CBC/Radio-Canada */
+
+/**
+ * @file
+ * Bitpacked
+ */
+
+#include "avcodec.h"
+#include "internal.h"
+#include "get_bits.h"
+#include "libavutil/imgutils.h"
+
+struct BitpackedContext {
+    int (*decode)(AVCodecContext *avctx, AVFrame *frame,
+                  AVPacket *pkt);
+};
+
+/* For this format, it's a simple passthrough */
+static int bitpacked_decode_uyvy422(AVCodecContext *avctx, AVFrame *frame,
+                                    AVPacket *avpkt)
+{
+    int ret;
+
+    /* there is no need to copy as the data already match
+     * a known pixel format */
+    frame->buf[0] = av_buffer_ref(avpkt->buf);
+    ret = av_image_fill_arrays(frame->data, frame->linesize, avpkt->data,
+                               avctx->pix_fmt, avctx->width, avctx->height, 1);
+    if (ret < 0) {
+        av_buffer_unref(&frame->buf[0]);
+        return ret;
+    }
+
+    return 0;
+}
+
+static int bitpacked_decode_yuv422p10(AVCodecContext *avctx, AVFrame *frame,
+                                      AVPacket *avpkt)
+{
+    uint64_t frame_size = (uint64_t)avctx->width * (uint64_t)avctx->height * 20;
+    uint64_t packet_size = avpkt->size * 8;
+    GetBitContext bc;
+    uint16_t *y, *u, *v;
+    int ret, i;
+
+    ret = ff_get_buffer(avctx, frame, 0);
+    if (ret < 0)
+        return ret;
+
+    y = (uint16_t*)frame->data[0];
+    u = (uint16_t*)frame->data[1];
+    v = (uint16_t*)frame->data[2];
+
+    if (frame_size > packet_size)
+        return AVERROR_INVALIDDATA;
+
+    if (avctx->width % 2)
+        return AVERROR_PATCHWELCOME;
+
+    ret = init_get_bits(&bc, avpkt->data, avctx->width * avctx->height * 20);
+    if (ret)
+        return ret;
+
+    for (i = 0; i < avctx->height; i++) {
+        y = (uint16_t*)(frame->data[0] + i * frame->linesize[0]);
+        u = (uint16_t*)(frame->data[1] + i * frame->linesize[1]);
+        v = (uint16_t*)(frame->data[2] + i * frame->linesize[2]);
+
+        for (int j = 0; j < avctx->width; j += 2) {
+            *u++ = get_bits(&bc, 10);
+            *y++ = get_bits(&bc, 10);
+            *v++ = get_bits(&bc, 10);
+            *y++ = get_bits(&bc, 10);
+        }
+    }
+
+    return 0;
+}
+
+static av_cold int bitpacked_init_decoder(AVCodecContext *avctx)
+{
+    struct BitpackedContext *bc = avctx->priv_data;
+
+    if (!avctx->codec_tag || !avctx->width || !avctx->height)
+        return AVERROR_INVALIDDATA;
+
+    if (avctx->codec_tag == MKTAG('U', 'Y', 'V', 'Y')) {
+        if (avctx->bits_per_coded_sample == 16 &&
+            avctx->pix_fmt == AV_PIX_FMT_UYVY422)
+            bc->decode = bitpacked_decode_uyvy422;
+        else if (avctx->bits_per_coded_sample == 20 &&
+                 avctx->pix_fmt == AV_PIX_FMT_YUV422P10)
+            bc->decode = bitpacked_decode_yuv422p10;
+        else
+            return AVERROR_INVALIDDATA;
+    } else {
+        return AVERROR_INVALIDDATA;
+    }
+
+    return 0;
+}
+
+static int bitpacked_decode(AVCodecContext *avctx, void *data, int *got_frame,
+                            AVPacket *avpkt)
+{
+    struct BitpackedContext *bc = avctx->priv_data;
+    int buf_size = avpkt->size;
+    AVFrame *frame = data;
+    int res;
+
+    frame->pict_type = AV_PICTURE_TYPE_I;
+    frame->key_frame = 1;
+
+    res = bc->decode(avctx, frame, avpkt);
+    if (res)
+        return res;
+
+    *got_frame = 1;
+    return buf_size;
+
+}
+
+AVCodec ff_bitpacked_decoder = {
+    .name   = "bitpacked",
+    .long_name = NULL_IF_CONFIG_SMALL("Bitpacked"),
+    .type = AVMEDIA_TYPE_VIDEO,
+    .id = AV_CODEC_ID_BITPACKED,
+    .priv_data_size        = sizeof(struct BitpackedContext),
+    .init = bitpacked_init_decoder,
+    .decode = bitpacked_decode,
+    .capabilities = AV_CODEC_CAP_EXPERIMENTAL,
+};