[FFmpeg-devel] [PATCH v4 1/2] codec: bitpacked: add decoder

Damien Riegel damien.riegel at savoirfairelinux.com
Fri Mar 31 18:36:15 EEST 2017


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 at savoirfairelinux.com>
---
Changes in v4:
 - use uint64_t for comparison between frame_size and packet_size
 - add a check to make sure width is even
 - take into account linesize to compute buffer addresses
 - use AVERROR_INVALIDDATA instead of custom error codes

Changes in v3:
 - Codec has been renamed bitpacked (instead of vrawdepay)
 - A decoding function is now chosen at codec init based on the pixel
   format
 - Codec marked as experimental

 libavcodec/Makefile     |   1 +
 libavcodec/allcodecs.c  |   1 +
 libavcodec/avcodec.h    |   1 +
 libavcodec/bitpacked.c  | 153 ++++++++++++++++++++++++++++++++++++++++++++++++
 libavcodec/codec_desc.c |   7 +++
 5 files changed, 163 insertions(+)
 create mode 100644 libavcodec/bitpacked.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 876a69e013..7a4eeaeac1 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -214,6 +214,7 @@ OBJS-$(CONFIG_BINK_DECODER)            += bink.o binkdsp.o
 OBJS-$(CONFIG_BINKAUDIO_DCT_DECODER)   += binkaudio.o
 OBJS-$(CONFIG_BINKAUDIO_RDFT_DECODER)  += binkaudio.o
 OBJS-$(CONFIG_BINTEXT_DECODER)         += bintext.o cga_data.o
+OBJS-$(CONFIG_BITPACKED_DECODER)       += bitpacked.o
 OBJS-$(CONFIG_BMP_DECODER)             += bmp.o msrledec.o
 OBJS-$(CONFIG_BMP_ENCODER)             += bmpenc.o
 OBJS-$(CONFIG_BMV_AUDIO_DECODER)       += bmvaudio.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index b7d03ad601..a746960add 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -362,6 +362,7 @@ static void register_all(void)
     REGISTER_DECODER(VP8,               vp8);
     REGISTER_DECODER(VP9,               vp9);
     REGISTER_DECODER(VQA,               vqa);
+    REGISTER_DECODER(BITPACKED,         bitpacked);
     REGISTER_DECODER(WEBP,              webp);
     REGISTER_ENCODER(WRAPPED_AVFRAME,   wrapped_avframe);
     REGISTER_ENCDEC (WMV1,              wmv1);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 60f7acefbd..7a26bf00d0 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -442,6 +442,7 @@ enum AVCodecID {
     AV_CODEC_ID_CLEARVIDEO,
     AV_CODEC_ID_XPM,
     AV_CODEC_ID_AV1,
+    AV_CODEC_ID_BITPACKED,
 
     /* various PCM "codecs" */
     AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs
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,
+};
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index 9711019e9d..4609e2c00e 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1381,6 +1381,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
         .long_name = NULL_IF_CONFIG_SMALL("Alliance for Open Media AV1"),
         .props     = AV_CODEC_PROP_LOSSY,
     },
+    {
+        .id        = AV_CODEC_ID_BITPACKED,
+        .type      = AVMEDIA_TYPE_VIDEO,
+        .name      = "bitpacked",
+        .long_name = NULL_IF_CONFIG_SMALL("Bitpacked"),
+        .props     = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSLESS,
+    },
 
     /* image codecs */
     {
-- 
2.12.0



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