avcodec: add PDV decoder

Changelog

@@ -3,6 +3,7 @@ releases are sorted from youngest to oldest.
 
 version <next>:
 - libaribcaption decoder
+- Playdate video decoder
 
 version 6.0:
 - Radiance HDR image support

configure

@@ -2899,6 +2899,7 @@ notchlc_decoder_select="lzf"
 nuv_decoder_select="idctdsp"
 opus_decoder_deps="swresample"
 opus_encoder_select="audio_frame_queue"
+pdv_decoder_deps="zlib"
 png_decoder_select="inflate_wrapper"
 png_encoder_select="deflate_wrapper llvidencdsp"
 prores_decoder_select="blockdsp idctdsp"

libavcodec/Makefile

@@ -583,6 +583,7 @@ OBJS-$(CONFIG_PBM_DECODER)             += pnmdec.o pnm.o
 OBJS-$(CONFIG_PBM_ENCODER)             += pnmenc.o
 OBJS-$(CONFIG_PCX_DECODER)             += pcx.o
 OBJS-$(CONFIG_PCX_ENCODER)             += pcxenc.o
+OBJS-$(CONFIG_PDV_DECODER)             += pdvdec.o
 OBJS-$(CONFIG_PFM_DECODER)             += pnmdec.o pnm.o
 OBJS-$(CONFIG_PFM_ENCODER)             += pnmenc.o
 OBJS-$(CONFIG_PGM_DECODER)             += pnmdec.o pnm.o

libavcodec/allcodecs.c

@@ -251,6 +251,7 @@ extern const FFCodec ff_pbm_encoder;
 extern const FFCodec ff_pbm_decoder;
 extern const FFCodec ff_pcx_encoder;
 extern const FFCodec ff_pcx_decoder;
+extern const FFCodec ff_pdv_decoder;
 extern const FFCodec ff_pfm_encoder;
 extern const FFCodec ff_pfm_decoder;
 extern const FFCodec ff_pgm_encoder;

libavcodec/codec_desc.c

@@ -1923,6 +1923,13 @@ static const AVCodecDescriptor codec_descriptors[] = {
         .long_name = NULL_IF_CONFIG_SMALL("ViewQuest VQC"),
         .props     = AV_CODEC_PROP_LOSSY,
     },
+    {
+        .id        = AV_CODEC_ID_PDV,
+        .type      = AVMEDIA_TYPE_VIDEO,
+        .name      = "pdv",
+        .long_name = NULL_IF_CONFIG_SMALL("PDV (PlayDate Video)"),
+        .props     = AV_CODEC_PROP_LOSSY,
+    },
 
     /* various PCM "codecs" */
     {

libavcodec/codec_id.h

@@ -320,6 +320,7 @@ enum AVCodecID {
     AV_CODEC_ID_WBMP,
     AV_CODEC_ID_MEDIA100,
     AV_CODEC_ID_VQC,
+    AV_CODEC_ID_PDV,
 
     /* various PCM "codecs" */
     AV_CODEC_ID_FIRST_AUDIO = 0x10000,     ///< A dummy id pointing at the start of audio codecs

libavcodec/pdvdec.c

@@ -0,0 +1,127 @@
+/*
+ * PDV video format
+ *
+ * Copyright (c) 2023 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 "avcodec.h"
+#include "codec_internal.h"
+#include "decode.h"
+#include "zlib_wrapper.h"
+
+#include <zlib.h>
+
+typedef struct PDVContext {
+    AVFrame  *previous_frame;
+    FFZStream zstream;
+} PDVContext;
+
+static av_cold int decode_init(AVCodecContext *avctx)
+{
+    PDVContext *s = avctx->priv_data;
+
+    avctx->pix_fmt = AV_PIX_FMT_MONOBLACK;
+
+    s->previous_frame = av_frame_alloc();
+    if (!s->previous_frame)
+        return AVERROR(ENOMEM);
+
+    return ff_inflate_init(&s->zstream, avctx);
+}
+
+static av_cold int decode_end(AVCodecContext *avctx)
+{
+    PDVContext *s = avctx->priv_data;
+
+    av_frame_free(&s->previous_frame);
+    ff_inflate_end(&s->zstream);
+
+    return 0;
+}
+
+static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
+                        int *got_frame, AVPacket *avpkt)
+{
+    PDVContext *s = avctx->priv_data;
+    AVFrame *prev_frame = s->previous_frame;
+    z_stream *const zstream = &s->zstream.zstream;
+    uint8_t *dst, *prev = prev_frame->data[0];
+    int ret, zret;
+
+    zret = inflateReset(zstream);
+    if (zret != Z_OK) {
+        av_log(avctx, AV_LOG_ERROR, "Could not reset inflate: %d.\n", zret);
+        return AVERROR_INVALIDDATA;
+    }
+
+    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
+        return ret;
+
+    zstream->next_in  = avpkt->data;
+    zstream->avail_in = avpkt->size;
+
+    dst = frame->data[0];
+    for (int i = 0; i < avctx->height; i++) {
+        zstream->next_out  = dst;
+        zstream->avail_out = (avctx->width + 7) >> 3;
+
+        zret = inflate(zstream, Z_SYNC_FLUSH);
+        if (zret != Z_OK && zret != Z_STREAM_END) {
+            av_log(avctx, AV_LOG_ERROR,
+                   "Inflate failed with return code: %d.\n", zret);
+            return AVERROR_INVALIDDATA;
+        }
+
+        if (!(avpkt->flags & AV_PKT_FLAG_KEY)) {
+            for (int j = 0; j < (avctx->width + 7) >> 3; j++)
+                dst[j] ^= prev[j];
+            prev += prev_frame->linesize[0];
+        }
+
+        dst += frame->linesize[0];
+    }
+
+    av_frame_unref(s->previous_frame);
+    if ((ret = av_frame_ref(s->previous_frame, frame)) < 0)
+        return ret;
+
+    if (avpkt->flags & AV_PKT_FLAG_KEY) {
+        frame->key_frame = 1;
+        frame->pict_type = AV_PICTURE_TYPE_I;
+    } else {
+        frame->pict_type = AV_PICTURE_TYPE_P;
+    }
+
+    *got_frame       = 1;
+
+    return avpkt->size;
+}
+
+const FFCodec ff_pdv_decoder = {
+    .p.name         = "pdv",
+    CODEC_LONG_NAME("PDV (PlayDate Video)"),
+    .priv_data_size = sizeof(PDVContext),
+    .p.type         = AVMEDIA_TYPE_VIDEO,
+    .p.id           = AV_CODEC_ID_PDV,
+    .p.capabilities = AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM,
+    .init           = decode_init,
+    .close          = decode_end,
+    FF_CODEC_DECODE_CB(decode_frame),
+};

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #include "version_major.h"
 
-#define LIBAVCODEC_VERSION_MINOR   9
+#define LIBAVCODEC_VERSION_MINOR  10
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \