CrystalHD decoder support v7

The Broadcom CrystalHD decoder chips provide hardware video
decoding for a number of video formats. It does so using a
memory:memory interface where a compressed bitstream is fed
in and decompressed pictures are copied out. As such, it works
independent of any graphics hardware in the system.

Features supported in this initial version:
* Support for Linux (using current drivers/library from git.wilsonet.com)
* Support for 70015 hardware
* Formats: MPEG2, MPEG4 Part 2, H.264, VC1 and DivX 3.11 (untested)
* Progressive content
* Non-H.264 Interlaced content
* H.264 MBAFF content

Features missing in this initial version:
* Support for OSX (might work - untested)
* Support for Windows
* Support for 70012 hardware
* H.264 PAFF content

Signed-off-by: Philip Langdale <philipl@overt.org>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

3 files changed, 967 insertions, 0 deletions

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 930affbb7a..3a99fcf4c1 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -26,6 +26,7 @@ OBJS = allcodecs.o                                                      \
 
 # parts needed for many different codecs
 OBJS-$(CONFIG_AANDCT)                  += aandcttab.o
+OBJS-$(CONFIG_CRYSTALHD)               += crystalhd.o
 OBJS-$(CONFIG_ENCODERS)                += faandct.o jfdctfst.o jfdctint.o
 OBJS-$(CONFIG_DCT)                     += dct.o
 OBJS-$(CONFIG_DWT)                     += dwt.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 108a3ab7c8..2fbe39552c 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -116,6 +116,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER (H263I, h263i);
     REGISTER_ENCODER (H263P, h263p);
     REGISTER_DECODER (H264, h264);
+    REGISTER_DECODER (H264_CRYSTALHD, h264_crystalhd);
     REGISTER_DECODER (H264_VDPAU, h264_vdpau);
     REGISTER_ENCDEC  (HUFFYUV, huffyuv);
     REGISTER_DECODER (IDCIN, idcin);
@@ -141,10 +142,13 @@ void avcodec_register_all(void)
     REGISTER_ENCDEC  (MPEG1VIDEO, mpeg1video);
     REGISTER_ENCDEC  (MPEG2VIDEO, mpeg2video);
     REGISTER_ENCDEC  (MPEG4, mpeg4);
+    REGISTER_DECODER (MPEG4_CRYSTALHD, mpeg4_crystalhd);
     REGISTER_DECODER (MPEG4_VDPAU, mpeg4_vdpau);
     REGISTER_DECODER (MPEGVIDEO, mpegvideo);
     REGISTER_DECODER (MPEG_VDPAU, mpeg_vdpau);
     REGISTER_DECODER (MPEG1_VDPAU, mpeg1_vdpau);
+    REGISTER_DECODER (MPEG2_CRYSTALHD, mpeg2_crystalhd);
+    REGISTER_DECODER (MSMPEG4_CRYSTALHD, msmpeg4_crystalhd);
     REGISTER_ENCDEC  (MSMPEG4V1, msmpeg4v1);
     REGISTER_ENCDEC  (MSMPEG4V2, msmpeg4v2);
     REGISTER_ENCDEC  (MSMPEG4V3, msmpeg4v3);
@@ -197,6 +201,7 @@ void avcodec_register_all(void)
     REGISTER_DECODER (V210X, v210x);
     REGISTER_DECODER (VB, vb);
     REGISTER_DECODER (VC1, vc1);
+    REGISTER_DECODER (VC1_CRYSTALHD, vc1_crystalhd);
     REGISTER_DECODER (VC1_VDPAU, vc1_vdpau);
     REGISTER_DECODER (VCR1, vcr1);
     REGISTER_DECODER (VMDVIDEO, vmdvideo);
@@ -211,6 +216,7 @@ void avcodec_register_all(void)
     REGISTER_ENCDEC  (WMV1, wmv1);
     REGISTER_ENCDEC  (WMV2, wmv2);
     REGISTER_DECODER (WMV3, wmv3);
+    REGISTER_DECODER (WMV3_CRYSTALHD, wmv3_crystalhd);
     REGISTER_DECODER (WMV3_VDPAU, wmv3_vdpau);
     REGISTER_DECODER (WNV1, wnv1);
     REGISTER_DECODER (XAN_WC3, xan_wc3);
diff --git a/libavcodec/crystalhd.c b/libavcodec/crystalhd.c
new file mode 100644
index 0000000000..209a86d62b
--- /dev/null
+++ b/libavcodec/crystalhd.c
@@ -0,0 +1,960 @@
+/*
+ * - CrystalHD decoder module -
+ *
+ * Copyright(C) 2010 Philip Langdale <ffmpeg.philipl@overt.org>
+ *
+ * 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
+ */
+
+/*
+ * - Principles of Operation -
+ *
+ * The CrystalHD decoder operates at the bitstream level - which is an even
+ * higher level than the decoding hardware you typically see in modern GPUs.
+ * This means it has a very simple interface, in principle. You feed demuxed
+ * packets in one end and get decoded picture (fields/frames) out the other.
+ *
+ * Of course, nothing is ever that simple. Due, at the very least, to b-frame
+ * dependencies in the supported formats, the hardware has a delay between
+ * when a packet goes in, and when a picture comes out. Furthermore, this delay
+ * is not just a function of time, but also one of the dependency on additional
+ * frames being fed into the decoder to satisfy the b-frame dependencies.
+ *
+ * As such, a pipeline will build up that is roughly equivalent to the required
+ * DPB for the file being played. If that was all it took, things would still
+ * be simple - so, of course, it isn't.
+ *
+ * The hardware has a way of indicating that a picture is ready to be copied out,
+ * but this is unreliable - and sometimes the attempt will still fail so, based
+ * on testing, the code will wait until 3 pictures are ready before starting
+ * to copy out - and this has the effect of extending the pipeline.
+ *
+ * Finally, while it is tempting to say that once the decoder starts outputing
+ * frames, the software should never fail to return a frame from a decode(),
+ * this is a hard assertion to make, because the stream may switch between
+ * differently encoded content (number of b-frames, interlacing, etc) which
+ * might require a longer pipeline than before. If that happened, you could
+ * deadlock trying to retrieve a frame that can't be decoded without feeding
+ * in additional packets.
+ *
+ * As such, the code will return in the event that a picture cannot be copied
+ * out, leading to an increase in the length of the pipeline. This in turn,
+ * means we have to be sensitive to the time it takes to decode a picture;
+ * We do not want to give up just because the hardware needed a little more
+ * time to prepare the picture! For this reason, there are delays included
+ * in the decode() path that ensure that, under normal conditions, the hardware
+ * will only fail to return a frame if it really needs additional packets to
+ * complete the decoding.
+ *
+ * Finally, to be explicit, we do not want the pipeline to grow without bound
+ * for two reasons: 1) The hardware can only buffer a finite number of packets,
+ * and 2) The client application may not be able to cope with arbitrarily long
+ * delays in the video path relative to the audio path. For example. MPlayer
+ * can only handle a 20 picture delay (although this is arbitrary, and needs
+ * to be extended to fully support the CrystalHD where the delay could be up
+ * to 32 pictures - consider PAFF H.264 content with 16 b-frames).
+ */
+
+/*****************************************************************************
+ * Includes
+ ****************************************************************************/
+
+#define _XOPEN_SOURCE 600
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <libcrystalhd/bc_dts_types.h>
+#include <libcrystalhd/bc_dts_defs.h>
+#include <libcrystalhd/libcrystalhd_if.h>
+
+#include "avcodec.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/intreadwrite.h"
+
+/* Timeout parameter passed to DtsProcOutput() in us */
+#define OUTPUT_PROC_TIMEOUT 50
+/* Step between fake timestamps passed to hardware in units of 100ns */
+#define TIMESTAMP_UNIT 100000
+/* Initial value in us of the wait in decode() */
+#define BASE_WAIT 10000
+/* Increment in us to adjust wait in decode() */
+#define WAIT_UNIT 1000
+
+
+/*****************************************************************************
+ * Module private data
+ ****************************************************************************/
+
+typedef enum {
+    RET_ERROR          = -1,
+    RET_OK             = 0,
+    RET_COPY_AGAIN     = 1,
+    RET_SKIP_NEXT_COPY = 2,
+} CopyRet;
+
+typedef struct OpaqueList {
+    struct OpaqueList *next;
+    uint64_t fake_timestamp;
+    uint64_t reordered_opaque;
+} OpaqueList;
+
+typedef struct {
+    AVCodecContext *avctx;
+    AVFrame pic;
+    HANDLE dev;
+
+    uint8_t is_70012;
+    uint8_t *sps_pps_buf;
+    uint32_t sps_pps_size;
+    uint8_t is_nal;
+    uint8_t output_ready;
+    uint8_t need_second_field;
+    uint8_t skip_next_output;
+    uint64_t decode_wait;
+
+    uint64_t last_picture;
+
+    OpaqueList *head;
+    OpaqueList *tail;
+} CHDContext;
+
+
+/*****************************************************************************
+ * Helper functions
+ ****************************************************************************/
+
+static inline BC_MEDIA_SUBTYPE id2subtype(CHDContext *priv, enum CodecID id)
+{
+    switch (id) {
+    case CODEC_ID_MPEG4:
+        return BC_MSUBTYPE_DIVX;
+    case CODEC_ID_MSMPEG4V3:
+        return BC_MSUBTYPE_DIVX311;
+    case CODEC_ID_MPEG2VIDEO:
+        return BC_MSUBTYPE_MPEG2VIDEO;
+    case CODEC_ID_VC1:
+        return BC_MSUBTYPE_VC1;
+    case CODEC_ID_WMV3:
+        return BC_MSUBTYPE_WMV3;
+    case CODEC_ID_H264:
+        return priv->is_nal ? BC_MSUBTYPE_AVC1 : BC_MSUBTYPE_H264;
+    default:
+        return BC_MSUBTYPE_INVALID;
+    }
+}
+
+static inline void print_frame_info(CHDContext *priv, BC_DTS_PROC_OUT *output)
+{
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tYBuffSz: %u\n", output->YbuffSz);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tYBuffDoneSz: %u\n",
+           output->YBuffDoneSz);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tUVBuffDoneSz: %u\n",
+           output->UVBuffDoneSz);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tTimestamp: %"PRIu64"\n",
+           output->PicInfo.timeStamp);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tPicture Number: %u\n",
+           output->PicInfo.picture_number);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tWidth: %u\n",
+           output->PicInfo.width);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tHeight: %u\n",
+           output->PicInfo.height);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tChroma: 0x%03x\n",
+           output->PicInfo.chroma_format);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tPulldown: %u\n",
+           output->PicInfo.pulldown);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tFlags: 0x%08x\n",
+           output->PicInfo.flags);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tFrame Rate/Res: %u\n",
+           output->PicInfo.frame_rate);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tAspect Ratio: %u\n",
+           output->PicInfo.aspect_ratio);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tColor Primaries: %u\n",
+           output->PicInfo.colour_primaries);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tMetaData: %u\n",
+           output->PicInfo.picture_meta_payload);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tSession Number: %u\n",
+           output->PicInfo.sess_num);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tycom: %u\n",
+           output->PicInfo.ycom);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tCustom Aspect: %u\n",
+           output->PicInfo.custom_aspect_ratio_width_height);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tFrames to Drop: %u\n",
+           output->PicInfo.n_drop);
+    av_log(priv->avctx, AV_LOG_VERBOSE, "\tH264 Valid Fields: 0x%08x\n",
+           output->PicInfo.other.h264.valid);
+}
+
+
+/*****************************************************************************
+ * OpaqueList functions
+ ****************************************************************************/
+
+static uint64_t opaque_list_push(CHDContext *priv, uint64_t reordered_opaque)
+{
+    OpaqueList *newNode = av_mallocz(sizeof (OpaqueList));
+    if (!newNode) {
+        av_log(priv->avctx, AV_LOG_ERROR,
+               "Unable to allocate new node in OpaqueList.\n");
+        return 0;
+    }
+    if (!priv->head) {
+        newNode->fake_timestamp = TIMESTAMP_UNIT;
+        priv->head              = newNode;
+    } else {
+        newNode->fake_timestamp = priv->tail->fake_timestamp + TIMESTAMP_UNIT;
+        priv->tail->next        = newNode;
+    }
+    priv->tail = newNode;
+    newNode->reordered_opaque = reordered_opaque;
+
+    return newNode->fake_timestamp;
+}
+
+/*
+ * The OpaqueList is built in decode order, while elements will be removed
+ * in presentation order. If frames are reordered, this means we must be
+ * able to remove elements that are not the first element.
+ */
+static uint64_t opaque_list_pop(CHDContext *priv, uint64_t fake_timestamp)
+{
+    OpaqueList *node = priv->head;
+
+    if (!priv->head) {
+        av_log(priv->avctx, AV_LOG_ERROR,
+               "CrystalHD: Attempted to query non-existent timestamps.\n");
+        return AV_NOPTS_VALUE;
+    }
+
+    /*
+     * The first element is special-cased because we have to manipulate
+     * the head pointer rather than the previous element in the list.
+     */
+    if (priv->head->fake_timestamp == fake_timestamp) {
+        uint64_t reordered_opaque = node->reordered_opaque;
+        priv->head = node->next;
+        av_free(node);
+
+        if (!priv->head->next)
+            priv->tail = priv->head;
+
+        return reordered_opaque;
+    }
+
+    /*
+     * The list is processed at arm's length so that we have the
+     * previous element available to rewrite its next pointer.
+     */
+    while (node->next) {
+        OpaqueList *next = node->next;
+        if (next->fake_timestamp == fake_timestamp) {
+            uint64_t reordered_opaque = next->reordered_opaque;
+            node->next = next->next;
+            av_free(next);
+
+            if (!node->next)
+               priv->tail = node;
+
+            return reordered_opaque;
+        } else {
+            node = next;
+        }
+    }
+
+    av_log(priv->avctx, AV_LOG_VERBOSE,
+           "CrystalHD: Couldn't match fake_timestamp.\n");
+    return AV_NOPTS_VALUE;
+}
+
+
+/*****************************************************************************
+ * Video decoder API function definitions
+ ****************************************************************************/
+
+static void flush(AVCodecContext *avctx)
+{
+    CHDContext *priv = avctx->priv_data;
+
+    avctx->has_b_frames     = 0;
+    priv->last_picture      = -1;
+    priv->output_ready      = 0;
+    priv->need_second_field = 0;
+    priv->skip_next_output  = 0;
+    priv->decode_wait       = BASE_WAIT;
+
+    if (priv->pic.data[0])
+        avctx->release_buffer(avctx, &priv->pic);
+
+    /* Flush mode 4 flushes all software and hardware buffers. */
+    DtsFlushInput(priv->dev, 4);
+}
+
+
+static av_cold int uninit(AVCodecContext *avctx)
+{
+    CHDContext *priv = avctx->priv_data;
+    HANDLE device;
+
+    device = priv->dev;
+    DtsStopDecoder(device);
+    DtsCloseDecoder(device);
+    DtsDeviceClose(device);
+
+    av_free(priv->sps_pps_buf);
+
+    if (priv->pic.data[0])
+        avctx->release_buffer(avctx, &priv->pic);
+
+    if (priv->head) {
+       OpaqueList *node = priv->head;
+       while (node) {
+          OpaqueList *next = node->next;
+          av_free(node);
+          node = next;
+       }
+    }
+
+    return 0;
+}
+
+
+static av_cold int init(AVCodecContext *avctx)
+{
+    CHDContext* priv;
+    BC_STATUS ret;
+    BC_INFO_CRYSTAL version;
+    BC_INPUT_FORMAT format = {
+        .FGTEnable   = FALSE,
+        .Progressive = TRUE,
+        .OptFlags    = 0x80000000 | vdecFrameRate59_94 | 0x40,
+        .width       = avctx->width,
+        .height      = avctx->height,
+    };
+
+    BC_MEDIA_SUBTYPE subtype;
+
+    uint32_t mode = DTS_PLAYBACK_MODE |
+                    DTS_LOAD_FILE_PLAY_FW |
+                    DTS_SKIP_TX_CHK_CPB |
+                    DTS_PLAYBACK_DROP_RPT_MODE |
+                    DTS_SINGLE_THREADED_MODE |
+                    DTS_DFLT_RESOLUTION(vdecRESOLUTION_1080p23_976);
+
+    av_log(avctx, AV_LOG_VERBOSE, "CrystalHD Init for %s\n",
+           avctx->codec->name);
+
+    avctx->pix_fmt = PIX_FMT_YUYV422;
+
+    /* Initialize the library */
+    priv               = avctx->priv_data;
+    priv->avctx        = avctx;
+    priv->is_nal       = avctx->extradata_size > 0 && *(avctx->extradata) == 1;
+    priv->last_picture = -1;
+    priv->decode_wait  = BASE_WAIT;
+
+    subtype = id2subtype(priv, avctx->codec->id);
+    switch (subtype) {
+    case BC_MSUBTYPE_AVC1:
+        {
+            uint8_t *dummy_p;
+            int dummy_int;
+            AVBitStreamFilterContext *bsfc;
+
+            uint32_t orig_data_size = avctx->extradata_size;
+            uint8_t *orig_data = av_malloc(orig_data_size);
+            if (!orig_data) {
+                av_log(avctx, AV_LOG_ERROR,
+                       "Failed to allocate copy of extradata\n");
+                return AVERROR(ENOMEM);
+            }
+            memcpy(orig_data, avctx->extradata, orig_data_size);
+
+
+            bsfc = av_bitstream_filter_init("h264_mp4toannexb");
+            if (!bsfc) {
+                av_log(avctx, AV_LOG_ERROR,
+                       "Cannot open the h264_mp4toannexb BSF!\n");
+                av_free(orig_data);
+                return AVERROR_BSF_NOT_FOUND;
+            }
+            av_bitstream_filter_filter(bsfc, avctx, NULL, &dummy_p,
+                                       &dummy_int, NULL, 0, 0);
+            av_bitstream_filter_close(bsfc);
+
+            priv->sps_pps_buf     = avctx->extradata;
+            priv->sps_pps_size    = avctx->extradata_size;
+            avctx->extradata      = orig_data;
+            avctx->extradata_size = orig_data_size;
+
+            format.pMetaData   = priv->sps_pps_buf;
+            format.metaDataSz  = priv->sps_pps_size;
+            format.startCodeSz = (avctx->extradata[4] & 0x03) + 1;
+        }
+        break;
+    case BC_MSUBTYPE_H264:
+        format.startCodeSz = 4;
+        // Fall-through
+    case BC_MSUBTYPE_VC1:
+    case BC_MSUBTYPE_WVC1:
+    case BC_MSUBTYPE_WMV3:
+    case BC_MSUBTYPE_WMVA:
+    case BC_MSUBTYPE_MPEG2VIDEO:
+    case BC_MSUBTYPE_DIVX:
+    case BC_MSUBTYPE_DIVX311:
+        format.pMetaData  = avctx->extradata;
+        format.metaDataSz = avctx->extradata_size;
+        break;
+    default:
+        av_log(avctx, AV_LOG_ERROR, "CrystalHD: Unknown codec name\n");
+        return AVERROR(EINVAL);
+    }
+    format.mSubtype = subtype;
+
+    /* Get a decoder instance */
+    av_log(avctx, AV_LOG_VERBOSE, "CrystalHD: starting up\n");
+    // Initialize the Link and Decoder devices
+    ret = DtsDeviceOpen(&priv->dev, mode);
+    if (ret != BC_STS_SUCCESS) {
+        av_log(avctx, AV_LOG_VERBOSE, "CrystalHD: DtsDeviceOpen failed\n");
+        goto fail;
+    }
+
+    ret = DtsCrystalHDVersion(priv->dev, &version);
+    if (ret != BC_STS_SUCCESS) {
+        av_log(avctx, AV_LOG_VERBOSE,
+               "CrystalHD: DtsCrystalHDVersion failed\n");
+        goto fail;
+    }
+    priv->is_70012 = version.device == 0;
+
+    if (priv->is_70012 &&
+        (subtype == BC_MSUBTYPE_DIVX || subtype == BC_MSUBTYPE_DIVX311)) {
+        av_log(avctx, AV_LOG_VERBOSE,
+               "CrystalHD: BCM70012 doesn't support MPEG4-ASP/DivX/Xvid\n");
+        goto fail;
+    }
+
+    ret = DtsSetInputFormat(priv->dev, &format);
+    if (ret != BC_STS_SUCCESS) {
+        av_log(avctx, AV_LOG_ERROR, "CrystalHD: SetInputFormat failed\n");
+        goto fail;
+    }
+
+    ret = DtsOpenDecoder(priv->dev, BC_STREAM_TYPE_ES);
+    if (ret != BC_STS_SUCCESS) {
+        av_log(avctx, AV_LOG_ERROR, "CrystalHD: DtsOpenDecoder failed\n");
+        goto fail;
+    }
+
+    ret = DtsSetColorSpace(priv->dev, OUTPUT_MODE422_YUY2);
+    if (ret != BC_STS_SUCCESS) {
+        av_log(avctx, AV_LOG_ERROR, "CrystalHD: DtsSetColorSpace failed\n");
+        goto fail;
+    }
+    ret = DtsStartDecoder(priv->dev);
+    if (ret != BC_STS_SUCCESS) {
+        av_log(avctx, AV_LOG_ERROR, "CrystalHD: DtsStartDecoder failed\n");
+        goto fail;
+    }
+    ret = DtsStartCapture(priv->dev);
+    if (ret != BC_STS_SUCCESS) {
+        av_log(avctx, AV_LOG_ERROR, "CrystalHD: DtsStartCapture failed\n");
+        goto fail;
+    }
+
+    av_log(avctx, AV_LOG_VERBOSE, "CrystalHD: Init complete.\n");
+
+    return 0;
+
+ fail:
+    uninit(avctx);
+    return -1;
+}
+
+
+/*
+ * The CrystalHD doesn't report interlaced H.264 content in a way that allows
+ * us to distinguish between specific cases that require different handling.
+ * So, for now, we have to hard-code the behaviour we want.
+ *
+ * The default behaviour is to assume MBAFF with input and output fieldpairs.
+ *
+ * Define ASSUME_PAFF_OVER_MBAFF to treat input as PAFF with separate input
+ * and output fields.
+ *
+ * Define ASSUME_TWO_INPUTS_ONE_OUTPUT to treat input as separate fields but
+ * output as a single fieldpair.
+ *
+ * Define both to mess up your playback.
+ */
+#define ASSUME_PAFF_OVER_MBAFF 0
+#define ASSUME_TWO_INPUTS_ONE_OUTPUT 0
+static inline CopyRet copy_frame(AVCodecContext *avctx,
+                                 BC_DTS_PROC_OUT *output,
+                                 void *data, int *data_size,
+                                 uint8_t second_field)
+{
+    BC_STATUS ret;
+    BC_DTS_STATUS decoder_status;
+    uint8_t is_paff;
+    uint8_t next_frame_same;
+    uint8_t interlaced;
+
+    CHDContext *priv = avctx->priv_data;
+
+    uint8_t bottom_field = (output->PicInfo.flags & VDEC_FLAG_BOTTOMFIELD) ==
+                           VDEC_FLAG_BOTTOMFIELD;
+    uint8_t bottom_first = !!(output->PicInfo.flags & VDEC_FLAG_BOTTOM_FIRST);
+
+    int width    = output->PicInfo.width;
+    int height   = output->PicInfo.height;
+    int bwidth;
+    uint8_t *src = output->Ybuff;
+    int sStride;
+    uint8_t *dst;
+    int dStride;
+
+    ret = DtsGetDriverStatus(priv->dev, &decoder_status);
+    if (ret != BC_STS_SUCCESS) {
+        av_log(avctx, AV_LOG_ERROR,
+               "CrystalHD: GetDriverStatus failed: %u\n", ret);
+       return RET_ERROR;
+    }
+
+    is_paff           = ASSUME_PAFF_OVER_MBAFF ||
+                        !(output->PicInfo.flags & VDEC_FLAG_UNKNOWN_SRC);
+    next_frame_same   = output->PicInfo.picture_number ==
+                        (decoder_status.picNumFlags & ~0x40000000);
+    interlaced        = ((output->PicInfo.flags &
+                          VDEC_FLAG_INTERLACED_SRC) && is_paff) ||
+                         next_frame_same || bottom_field || second_field;
+
+    av_log(avctx, AV_LOG_VERBOSE, "CrystalHD: next_frame_same: %u | %u | %u\n",
+           next_frame_same, output->PicInfo.picture_number,
+           decoder_status.picNumFlags & ~0x40000000);
+
+    if (priv->pic.data[0] && !priv->need_second_field)
+        avctx->release_buffer(avctx, &priv->pic);
+
+    priv->need_second_field = interlaced && !priv->need_second_field;
+
+    priv->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
+                             FF_BUFFER_HINTS_REUSABLE;
+    if (!priv->pic.data[0]) {
+        if (avctx->get_buffer(avctx, &priv->pic) < 0) {
+            av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+            return RET_ERROR;
+        }
+    }
+
+    bwidth = av_image_get_linesize(avctx->pix_fmt, width, 0);
+    if (priv->is_70012) {
+        int pStride;
+
+        if (width <= 720)
+            pStride = 720;
+        else if (width <= 1280)
+            pStride = 1280;
+        else if (width <= 1080)
+            pStride = 1080;
+        sStride = av_image_get_linesize(avctx->pix_fmt, pStride, 0);
+    } else {
+        sStride = bwidth;
+    }
+
+    dStride = priv->pic.linesize[0];
+    dst     = priv->pic.data[0];
+
+    av_log(priv->avctx, AV_LOG_VERBOSE, "CrystalHD: Copying out frame\n");
+
+    if (interlaced) {
+        int dY = 0;
+        int sY = 0;
+
+        height /= 2;
+        if (bottom_field) {
+            av_log(priv->avctx, AV_LOG_VERBOSE, "Interlaced: bottom field\n");
+            dY = 1;
+        } else {
+            av_log(priv->avctx, AV_LOG_VERBOSE, "Interlaced: top field\n");
+            dY = 0;
+        }
+
+        for (sY = 0; sY < height; dY++, sY++) {
+            memcpy(&(dst[dY * dStride]), &(src[sY * sStride]), bwidth);
+            if (interlaced)
+                dY++;
+        }
+    } else {
+        av_image_copy_plane(dst, dStride, src, sStride, bwidth, height);
+    }
+
+    priv->pic.interlaced_frame = interlaced;
+    if (interlaced)
+        priv->pic.top_field_first = !bottom_first;
+
+    if (output->PicInfo.timeStamp != 0) {
+        priv->pic.pkt_pts = opaque_list_pop(priv, output->PicInfo.timeStamp);
+        av_log(avctx, AV_LOG_VERBOSE, "output \"pts\": %"PRIu64"\n",
+               priv->pic.pkt_pts);
+    }
+
+    if (!priv->need_second_field) {
+        *data_size       = sizeof(AVFrame);
+        *(AVFrame *)data = priv->pic;
+    }
+
+    if (ASSUME_TWO_INPUTS_ONE_OUTPUT &&
+        output->PicInfo.flags & VDEC_FLAG_UNKNOWN_SRC) {
+        av_log(priv->avctx, AV_LOG_VERBOSE, "Fieldpair from two packets.\n");
+        return RET_SKIP_NEXT_COPY;
+    }
+
+    return RET_OK;
+}
+
+
+static inline CopyRet receive_frame(AVCodecContext *avctx,
+                                    void *data, int *data_size,
+                                    uint8_t second_field)
+{
+    BC_STATUS ret;
+    BC_DTS_PROC_OUT output = {
+        .PicInfo.width  = avctx->width,
+        .PicInfo.height = avctx->height,
+    };
+    CHDContext *priv = avctx->priv_data;
+    HANDLE dev       = priv->dev;
+
+    *data_size = 0;
+
+    // Request decoded data from the driver
+    ret = DtsProcOutputNoCopy(dev, OUTPUT_PROC_TIMEOUT, &output);
+    if (ret == BC_STS_FMT_CHANGE) {
+        av_log(avctx, AV_LOG_VERBOSE, "CrystalHD: Initial format change\n");
+        avctx->width  = output.PicInfo.width;
+        avctx->height = output.PicInfo.height;
+        return RET_COPY_AGAIN;
+    } else if (ret == BC_STS_SUCCESS) {
+        int copy_ret = -1;
+        if (output.PoutFlags & BC_POUT_FLAGS_PIB_VALID) {
+            if (priv->last_picture == -1) {
+                /*
+                 * Init to one less, so that the incrementing code doesn't
+                 * need to be special-cased.
+                 */
+                priv->last_picture = output.PicInfo.picture_number - 1;
+            }
+
+            if (avctx->codec->id == CODEC_ID_MPEG4 &&
+                output.PicInfo.timeStamp == 0) {
+                av_log(avctx, AV_LOG_VERBOSE,
+                       "CrystalHD: Not returning packed frame twice.\n");
+                priv->last_picture++;
+                DtsReleaseOutputBuffs(dev, NULL, FALSE);
+                return RET_COPY_AGAIN;
+            }
+
+            print_frame_info(priv, &output);
+
+            if (priv->last_picture + 1 < output.PicInfo.picture_number) {
+                av_log(avctx, AV_LOG_WARNING,
+                       "CrystalHD: Picture Number discontinuity\n");
+                /*
+                 * Have we lost frames? If so, we need to shrink the
+                 * pipeline length appropriately.
+                 *
+                 * XXX: I have no idea what the semantics of this situation
+                 * are so I don't even know if we've lost frames or which
+                 * ones.
+                 *
+                 * In any case, only warn the first time.
+                 */
+               priv->last_picture = output.PicInfo.picture_number - 1;
+            }
+
+            copy_ret = copy_frame(avctx, &output, data, data_size, second_field);
+            if (*data_size > 0) {
+                avctx->has_b_frames--;
+                priv->last_picture++;
+                av_log(avctx, AV_LOG_VERBOSE, "CrystalHD: Pipeline length: %u\n",
+                       avctx->has_b_frames);
+            }
+        } else {
+            /*
+             * An invalid frame has been consumed.
+             */
+            av_log(avctx, AV_LOG_ERROR, "CrystalHD: ProcOutput succeeded with "
+                                        "invalid PIB\n");
+            avctx->has_b_frames--;
+            copy_ret = RET_OK;
+        }
+        DtsReleaseOutputBuffs(dev, NULL, FALSE);
+
+        return copy_ret;
+    } else if (ret == BC_STS_BUSY) {
+        return RET_COPY_AGAIN;
+    } else {
+        av_log(avctx, AV_LOG_ERROR, "CrystalHD: ProcOutput failed %d\n", ret);
+        return RET_ERROR;
+    }
+}
+
+
+static int decode(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
+{
+    BC_STATUS ret;
+    BC_DTS_STATUS decoder_status;
+    CopyRet rec_ret;
+    CHDContext *priv   = avctx->priv_data;
+    HANDLE dev         = priv->dev;
+    int len            = avpkt->size;
+
+    av_log(avctx, AV_LOG_VERBOSE, "CrystalHD: decode_frame\n");
+
+    if (len) {
+        int32_t tx_free = (int32_t)DtsTxFreeSize(dev);
+        if (len < tx_free - 1024) {
+            /*
+             * Despite being notionally opaque, either libcrystalhd or
+             * the hardware itself will mangle pts values that are too
+             * small or too large. The docs claim it should be in units
+             * of 100ns. Given that we're nominally dealing with a black
+             * box on both sides, any transform we do has no guarantee of
+             * avoiding mangling so we need to build a mapping to values
+             * we know will not be mangled.
+             */
+            uint64_t pts = opaque_list_push(priv, avctx->pkt->pts);
+            if (!pts) {
+                return AVERROR(ENOMEM);
+            }
+            av_log(priv->avctx, AV_LOG_VERBOSE,
+                   "input \"pts\": %"PRIu64"\n", pts);
+            ret = DtsProcInput(dev, avpkt->data, len, pts, 0);
+            if (ret == BC_STS_BUSY) {
+                av_log(avctx, AV_LOG_WARNING,
+                       "CrystalHD: ProcInput returned busy\n");
+                usleep(BASE_WAIT);
+                return AVERROR(EBUSY);
+            } else if (ret != BC_STS_SUCCESS) {
+                av_log(avctx, AV_LOG_ERROR,
+                       "CrystalHD: ProcInput failed: %u\n", ret);
+                return -1;
+            }
+            avctx->has_b_frames++;
+        } else {
+            av_log(avctx, AV_LOG_WARNING, "CrystalHD: Input buffer full\n");
+            len = 0; // We didn't consume any bytes.
+        }
+    } else {
+        av_log(avctx, AV_LOG_INFO, "CrystalHD: No more input data\n");
+    }
+
+    if (priv->skip_next_output) {
+        av_log(avctx, AV_LOG_VERBOSE, "CrystalHD: Skipping next output.\n");
+        priv->skip_next_output = 0;
+        avctx->has_b_frames--;
+        return len;
+    }
+
+    ret = DtsGetDriverStatus(dev, &decoder_status);
+    if (ret != BC_STS_SUCCESS) {
+        av_log(avctx, AV_LOG_ERROR, "CrystalHD: GetDriverStatus failed\n");
+        return -1;
+    }
+
+    /*
+     * No frames ready. Don't try to extract.
+     *
+     * Empirical testing shows that ReadyListCount can be a damn lie,
+     * and ProcOut still fails when count > 0. The same testing showed
+     * that two more iterations were needed before ProcOutput would
+     * succeed.
+     */
+    if (priv->output_ready < 2) {
+        if (decoder_status.ReadyListCount != 0)
+            priv->output_ready++;
+        usleep(BASE_WAIT);
+        av_log(avctx, AV_LOG_INFO, "CrystalHD: Filling pipeline.\n");
+        return len;
+    } else if (decoder_status.ReadyListCount == 0) {
+        /*
+         * After the pipeline is established, if we encounter a lack of frames
+         * that probably means we're not giving the hardware enough time to
+         * decode them, so start increasing the wait time at the end of a
+         * decode call.
+         */
+        usleep(BASE_WAIT);
+        priv->decode_wait += WAIT_UNIT;
+        av_log(avctx, AV_LOG_INFO, "CrystalHD: No frames ready. Returning\n");
+        return len;
+    }
+
+    do {
+        rec_ret = receive_frame(avctx, data, data_size, 0);
+        if (rec_ret == 0 && *data_size == 0) {
+            if (avctx->codec->id == CODEC_ID_H264) {
+                /*
+                 * This case is for when the encoded fields are stored
+                 * separately and we get a separate avpkt for each one. To keep
+                 * the pipeline stable, we should return nothing and wait for
+                 * the next time round to grab the second field.
+                 * H.264 PAFF is an example of this.
+                 */
+                av_log(avctx, AV_LOG_VERBOSE, "Returning after first field.\n");
+                avctx->has_b_frames--;
+            } else {
+                /*
+                 * This case is for when the encoded fields are stored in a
+                 * single avpkt but the hardware returns then separately. Unless
+                 * we grab the second field before returning, we'll slip another
+                 * frame in the pipeline and if that happens a lot, we're sunk.
+                 * So we have to get that second field now.
+                 * Interlaced mpeg2 and vc1 are examples of this.
+                 */
+                av_log(avctx, AV_LOG_VERBOSE, "Trying to get second field.\n");
+                while (1) {
+                    usleep(priv->decode_wait);
+                    ret = DtsGetDriverStatus(dev, &decoder_status);
+                    if (ret == BC_STS_SUCCESS &&
+                        decoder_status.ReadyListCount > 0) {
+                        rec_ret = receive_frame(avctx, data, data_size, 1);
+                        if ((rec_ret == 0 && *data_size > 0) ||
+                            rec_ret == RET_ERROR)
+                            break;
+                    }
+                }
+                av_log(avctx, AV_LOG_VERBOSE, "CrystalHD: Got second field.\n");
+            }
+        } else if (rec_ret == RET_SKIP_NEXT_COPY) {
+            /*
+             * Two input packets got turned into a field pair. Gawd.
+             */
+            av_log(avctx, AV_LOG_VERBOSE,
+                   "Don't output on next decode call.\n");
+            priv->skip_next_output = 1;
+        }
+        /*
+         * If rec_ret == RET_COPY_AGAIN, that means that either we just handled
+         * a FMT_CHANGE event and need to go around again for the actual frame,
+         * we got a busy status and need to try again, or we're dealing with
+         * packed b-frames, where the hardware strangely returns the packed
+         * p-frame twice. We choose to keep the second copy as it carries the
+         * valid pts.
+         */
+    } while (rec_ret == RET_COPY_AGAIN);
+    usleep(priv->decode_wait);
+    return len;
+}
+
+
+#if CONFIG_H264_CRYSTALHD_DECODER
+AVCodec ff_h264_crystalhd_decoder = {
+    .name           = "h264_crystalhd",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_H264,
+    .priv_data_size = sizeof(CHDContext),
+    .init           = init,
+    .close          = uninit,
+    .decode         = decode,
+    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DELAY | CODEC_CAP_EXPERIMENTAL,
+    .flush          = flush,
+    .long_name      = NULL_IF_CONFIG_SMALL("H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (CrystalHD acceleration)"),
+    .pix_fmts       = (const enum PixelFormat[]){PIX_FMT_YUYV422, PIX_FMT_NONE},
+};
+#endif
+
+#if CONFIG_MPEG2_CRYSTALHD_DECODER
+AVCodec ff_mpeg2_crystalhd_decoder = {
+    .name           = "mpeg2_crystalhd",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_MPEG2VIDEO,
+    .priv_data_size = sizeof(CHDContext),
+    .init           = init,
+    .close          = uninit,
+    .decode         = decode,
+    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DELAY | CODEC_CAP_EXPERIMENTAL,
+    .flush          = flush,
+    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-2 Video (CrystalHD acceleration)"),
+    .pix_fmts       = (const enum PixelFormat[]){PIX_FMT_YUYV422, PIX_FMT_NONE},
+};
+#endif
+
+#if CONFIG_MPEG4_CRYSTALHD_DECODER
+AVCodec ff_mpeg4_crystalhd_decoder = {
+    .name           = "mpeg4_crystalhd",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_MPEG4,
+    .priv_data_size = sizeof(CHDContext),
+    .init           = init,
+    .close          = uninit,
+    .decode         = decode,
+    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DELAY | CODEC_CAP_EXPERIMENTAL,
+    .flush          = flush,
+    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 Part 2 (CrystalHD acceleration)"),
+    .pix_fmts       = (const enum PixelFormat[]){PIX_FMT_YUYV422, PIX_FMT_NONE},
+};
+#endif
+
+#if CONFIG_MSMPEG4_CRYSTALHD_DECODER
+AVCodec ff_msmpeg4_crystalhd_decoder = {
+    .name           = "msmpeg4_crystalhd",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_MSMPEG4V3,
+    .priv_data_size = sizeof(CHDContext),
+    .init           = init,
+    .close          = uninit,
+    .decode         = decode,
+    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DELAY | CODEC_CAP_EXPERIMENTAL,
+    .flush          = flush,
+    .long_name      = NULL_IF_CONFIG_SMALL("MPEG-4 Part 2 Microsoft variant version 3 (CrystalHD acceleration)"),
+    .pix_fmts       = (const enum PixelFormat[]){PIX_FMT_YUYV422, PIX_FMT_NONE},
+};
+#endif
+
+#if CONFIG_VC1_CRYSTALHD_DECODER
+AVCodec ff_vc1_crystalhd_decoder = {
+    .name           = "vc1_crystalhd",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_VC1,
+    .priv_data_size = sizeof(CHDContext),
+    .init           = init,
+    .close          = uninit,
+    .decode         = decode,
+    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DELAY | CODEC_CAP_EXPERIMENTAL,
+    .flush          = flush,
+    .long_name      = NULL_IF_CONFIG_SMALL("SMPTE VC-1 (CrystalHD acceleration)"),
+    .pix_fmts       = (const enum PixelFormat[]){PIX_FMT_YUYV422, PIX_FMT_NONE},
+};
+#endif
+
+#if CONFIG_WMV3_CRYSTALHD_DECODER
+AVCodec ff_wmv3_crystalhd_decoder = {
+    .name           = "wmv3_crystalhd",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_WMV3,
+    .priv_data_size = sizeof(CHDContext),
+    .init           = init,
+    .close          = uninit,
+    .decode         = decode,
+    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_DELAY | CODEC_CAP_EXPERIMENTAL,
+    .flush          = flush,
+    .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Video 9 (CrystalHD acceleration)"),
+    .pix_fmts       = (const enum PixelFormat[]){PIX_FMT_YUYV422, PIX_FMT_NONE},
+};
+#endif