PeerStreamer

/*

 * - CrystalHD decoder module -

 *

 * Copyright(C) 2010,2011 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,

    RET_COPY_NEXT_FIELD = 3,

} 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);

            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;

    }

    /*

     * Testing has shown that in all cases where we don't want to return the

     * full frame immediately, VDEC_FLAG_UNKNOWN_SRC is set.

     */

    return priv->need_second_field &&

           !(output->PicInfo.flags & VDEC_FLAG_UNKNOWN_SRC) ?

           RET_COPY_NEXT_FIELD : 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 == RET_OK && *data_size == 0) {

            /*

             * 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 if (rec_ret == RET_COPY_NEXT_FIELD) {

            /*

             * 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 == RET_OK && *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