/*
  * Microsoft XMV demuxer
  * Copyright (c) 2011 Sven Hesse <drmccoy@drmccoy.de>
  * Copyright (c) 2011 Matthew Hoops <clone2727@gmail.com>
  *

  * 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
  */
 
 /**
  * @file
  * Microsoft XMV demuxer
  */
 

 #include <inttypes.h>

 
 #include "libavutil/intreadwrite.h"
 
 #include "avformat.h"

 #include "internal.h"

 #include "riff.h"

 #include "libavutil/avassert.h"

 /** The min size of an XMV header. */

 #define XMV_MIN_HEADER_SIZE 36
 

 /** Audio flag: ADPCM'd 5.1 stream, front left / right channels */

 #define XMV_AUDIO_ADPCM51_FRONTLEFTRIGHT 1

 /** Audio flag: ADPCM'd 5.1 stream, front center / low frequency channels */

 #define XMV_AUDIO_ADPCM51_FRONTCENTERLOW 2

 /** Audio flag: ADPCM'd 5.1 stream, rear left / right channels */

 #define XMV_AUDIO_ADPCM51_REARLEFTRIGHT  4
 

 /** Audio flag: Any of the ADPCM'd 5.1 stream flags. */

 #define XMV_AUDIO_ADPCM51 (XMV_AUDIO_ADPCM51_FRONTLEFTRIGHT | \
                            XMV_AUDIO_ADPCM51_FRONTCENTERLOW | \
                            XMV_AUDIO_ADPCM51_REARLEFTRIGHT)
 

 #define XMV_BLOCK_ALIGN_SIZE 36
 

 /** A video packet with an XMV file. */

 typedef struct XMVVideoPacket {

     int created;

     int stream_index; ///< The decoder stream index for this video packet.

     uint32_t data_size;   ///< The size of the remaining video data.
     uint64_t data_offset; ///< The offset of the video data within the file.

     uint32_t current_frame; ///< The current frame within this video packet.
     uint32_t frame_count;   ///< The amount of frames within this video packet.

     int     has_extradata; ///< Does the video packet contain extra data?
     uint8_t extradata[4];  ///< The extra data

     int64_t last_pts; ///< PTS of the last video frame.
     int64_t pts;      ///< PTS of the most current video frame.

 } XMVVideoPacket;
 

 /** An audio packet with an XMV file. */

 typedef struct XMVAudioPacket {

     int created;

     int stream_index; ///< The decoder stream index for this audio packet.

     /* Stream format properties. */
     uint16_t compression;     ///< The type of compression.
     uint16_t channels;        ///< Number of channels.

     int32_t sample_rate;      ///< Sampling rate.

     uint16_t bits_per_sample; ///< Bits per compressed sample.
     uint32_t bit_rate;        ///< Bits of compressed data per second.
     uint16_t flags;           ///< Flags

     unsigned block_align;     ///< Bytes per compressed block.

     uint16_t block_samples;   ///< Decompressed samples per compressed block.

     enum AVCodecID codec_id; ///< The codec ID of the compression scheme.

     uint32_t data_size;   ///< The size of the remaining audio data.
     uint64_t data_offset; ///< The offset of the audio data within the file.

     uint32_t frame_size; ///< Number of bytes to put into an audio frame.

     uint64_t block_count; ///< Running counter of decompressed audio block.

 } XMVAudioPacket;
 

 /** Context for demuxing an XMV file. */

 typedef struct XMVDemuxContext {

     uint16_t audio_track_count; ///< Number of audio track in this file.

     uint32_t this_packet_size; ///< Size of the current packet.
     uint32_t next_packet_size; ///< Size of the next packet.

     uint64_t this_packet_offset; ///< Offset of the current packet.
     uint64_t next_packet_offset; ///< Offset of the next packet.

     uint16_t current_stream; ///< The index of the stream currently handling.
     uint16_t stream_count;   ///< The number of streams in this file.

     uint32_t video_duration;
     uint32_t video_width;
     uint32_t video_height;

     XMVVideoPacket  video; ///< The video packet contained in each packet.
     XMVAudioPacket *audio; ///< The audio packets contained in each packet.

 } XMVDemuxContext;
 
 static int xmv_probe(AVProbeData *p)
 {
     uint32_t file_version;
 
     if (p->buf_size < XMV_MIN_HEADER_SIZE)
         return 0;
 
     file_version = AV_RL32(p->buf + 16);
     if ((file_version == 0) || (file_version > 4))
         return 0;
 
     if (!memcmp(p->buf + 12, "xobX", 4))
         return AVPROBE_SCORE_MAX;
 
     return 0;
 }
 

 static int xmv_read_close(AVFormatContext *s)
 {
     XMVDemuxContext *xmv = s->priv_data;
 

     av_freep(&xmv->audio);

 
     return 0;
 }
 

 static int xmv_read_header(AVFormatContext *s)

 {
     XMVDemuxContext *xmv = s->priv_data;
     AVIOContext     *pb  = s->pb;
 
     uint32_t file_version;
     uint32_t this_packet_size;
     uint16_t audio_track;

     int ret;

     s->ctx_flags |= AVFMTCTX_NOHEADER;
 

     avio_skip(pb, 4); /* Next packet size */
 
     this_packet_size = avio_rl32(pb);
 
     avio_skip(pb, 4); /* Max packet size */
     avio_skip(pb, 4); /* "xobX" */
 
     file_version = avio_rl32(pb);
     if ((file_version != 4) && (file_version != 2))

         avpriv_request_sample(s, "Uncommon version %"PRIu32"", file_version);

     /* Video tracks */

     xmv->video_width    = avio_rl32(pb);
     xmv->video_height   = avio_rl32(pb);
     xmv->video_duration = avio_rl32(pb);

 
     /* Audio tracks */
 
     xmv->audio_track_count = avio_rl16(pb);
 
     avio_skip(pb, 2); /* Unknown (padding?) */
 

     xmv->audio = av_mallocz_array(xmv->audio_track_count, sizeof(XMVAudioPacket));

     if (!xmv->audio) {
         ret = AVERROR(ENOMEM);
         goto fail;
     }

 
     for (audio_track = 0; audio_track < xmv->audio_track_count; audio_track++) {

         XMVAudioPacket *packet = &xmv->audio[audio_track];

         packet->compression     = avio_rl16(pb);
         packet->channels        = avio_rl16(pb);
         packet->sample_rate     = avio_rl32(pb);
         packet->bits_per_sample = avio_rl16(pb);
         packet->flags           = avio_rl16(pb);
 
         packet->bit_rate      = packet->bits_per_sample *
                                 packet->sample_rate *
                                 packet->channels;

         packet->block_align   = XMV_BLOCK_ALIGN_SIZE * packet->channels;

         packet->block_samples = 64;
         packet->codec_id      = ff_wav_codec_get_id(packet->compression,
                                                     packet->bits_per_sample);
 

         packet->stream_index = -1;
 
         packet->frame_size  = 0;
         packet->block_count = 0;
 
         /* TODO: ADPCM'd 5.1 sound is encoded in three separate streams.
          *       Those need to be interleaved to a proper 5.1 stream. */

         if (packet->flags & XMV_AUDIO_ADPCM51)

             av_log(s, AV_LOG_WARNING, "Unsupported 5.1 ADPCM audio stream "

                                       "(0x%04X)\n", packet->flags);

         if (!packet->channels || packet->sample_rate <= 0 ||

              packet->channels >= UINT16_MAX / XMV_BLOCK_ALIGN_SIZE) {

             av_log(s, AV_LOG_ERROR, "Invalid parameters for audio track %"PRIu16".\n",

                    audio_track);
             ret = AVERROR_INVALIDDATA;
             goto fail;
         }

     }
 
 

     /* Initialize the packet context */

 
     xmv->next_packet_offset = avio_tell(pb);

     xmv->next_packet_size   = this_packet_size - xmv->next_packet_offset;
     xmv->stream_count       = xmv->audio_track_count + 1;

 
     return 0;

 
 fail:
     xmv_read_close(s);
     return ret;

 }
 
 static void xmv_read_extradata(uint8_t *extradata, AVIOContext *pb)
 {
     /* Read the XMV extradata */
 
     uint32_t data = avio_rl32(pb);
 
     int mspel_bit        = !!(data & 0x01);
     int loop_filter      = !!(data & 0x02);
     int abt_flag         = !!(data & 0x04);
     int j_type_bit       = !!(data & 0x08);
     int top_left_mv_flag = !!(data & 0x10);
     int per_mb_rl_bit    = !!(data & 0x20);
     int slice_count      = (data >> 6) & 7;
 
     /* Write it back as standard WMV2 extradata */
 
     data = 0;
 
     data |= mspel_bit        << 15;
     data |= loop_filter      << 14;
     data |= abt_flag         << 13;
     data |= j_type_bit       << 12;
     data |= top_left_mv_flag << 11;
     data |= per_mb_rl_bit    << 10;
     data |= slice_count      <<  7;
 
     AV_WB32(extradata, data);
 }
 
 static int xmv_process_packet_header(AVFormatContext *s)
 {
     XMVDemuxContext *xmv = s->priv_data;
     AVIOContext     *pb  = s->pb;

     int ret;

 
     uint8_t  data[8];
     uint16_t audio_track;

     uint64_t data_offset;

 
     /* Next packet size */
     xmv->next_packet_size = avio_rl32(pb);
 
     /* Packet video header */
 
     if (avio_read(pb, data, 8) != 8)
         return AVERROR(EIO);
 
     xmv->video.data_size     = AV_RL32(data) & 0x007FFFFF;
 
     xmv->video.current_frame = 0;
     xmv->video.frame_count   = (AV_RL32(data) >> 23) & 0xFF;
 
     xmv->video.has_extradata = (data[3] & 0x80) != 0;
 

     if (!xmv->video.created) {
         AVStream *vst = avformat_new_stream(s, NULL);
         if (!vst)
             return AVERROR(ENOMEM);
 
         avpriv_set_pts_info(vst, 32, 1, 1000);
 
         vst->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
         vst->codecpar->codec_id   = AV_CODEC_ID_WMV2;
         vst->codecpar->codec_tag  = MKBETAG('W', 'M', 'V', '2');
         vst->codecpar->width      = xmv->video_width;
         vst->codecpar->height     = xmv->video_height;
 
         vst->duration = xmv->video_duration;
 
         xmv->video.stream_index = vst->index;
 
         xmv->video.created = 1;
     }
 

     /* Adding the audio data sizes and the video data size keeps you 4 bytes
      * short for every audio track. But as playing around with XMV files with
      * ADPCM audio showed, taking the extra 4 bytes from the audio data gives
      * you either completely distorted audio or click (when skipping the

      * remaining 68 bytes of the ADPCM block). Subtracting 4 bytes for every

      * audio track from the video data works at least for the audio. Probably
      * some alignment thing?
      * The video data has (always?) lots of padding, so it should work out...
      */
     xmv->video.data_size -= xmv->audio_track_count * 4;
 
     xmv->current_stream = 0;
     if (!xmv->video.frame_count) {
         xmv->video.frame_count = 1;

         xmv->current_stream    = xmv->stream_count > 1;

     }
 
     /* Packet audio header */
 
     for (audio_track = 0; audio_track < xmv->audio_track_count; audio_track++) {
         XMVAudioPacket *packet = &xmv->audio[audio_track];
 
         if (avio_read(pb, data, 4) != 4)
             return AVERROR(EIO);
 

         if (!packet->created) {
             AVStream *ast = avformat_new_stream(s, NULL);
             if (!ast)
                 return AVERROR(ENOMEM);
 
             ast->codecpar->codec_type            = AVMEDIA_TYPE_AUDIO;
             ast->codecpar->codec_id              = packet->codec_id;
             ast->codecpar->codec_tag             = packet->compression;
             ast->codecpar->channels              = packet->channels;
             ast->codecpar->sample_rate           = packet->sample_rate;
             ast->codecpar->bits_per_coded_sample = packet->bits_per_sample;
             ast->codecpar->bit_rate              = packet->bit_rate;
             ast->codecpar->block_align           = 36 * packet->channels;
 
             avpriv_set_pts_info(ast, 32, packet->block_samples, packet->sample_rate);
 
             packet->stream_index = ast->index;
 
             ast->duration = xmv->video_duration;
 
             packet->created = 1;
         }
 

         packet->data_size = AV_RL32(data) & 0x007FFFFF;
         if ((packet->data_size == 0) && (audio_track != 0))
             /* This happens when I create an XMV with several identical audio
              * streams. From the size calculations, duplicating the previous
              * stream's size works out, but the track data itself is silent.
              * Maybe this should also redirect the offset to the previous track?
              */
             packet->data_size = xmv->audio[audio_track - 1].data_size;
 

         /* Carve up the audio data in frame_count slices */

         packet->frame_size  = packet->data_size  / xmv->video.frame_count;

         packet->frame_size -= packet->frame_size % packet->block_align;

     }
 
     /* Packet data offsets */
 
     data_offset = avio_tell(pb);
 
     xmv->video.data_offset = data_offset;
     data_offset += xmv->video.data_size;
 
     for (audio_track = 0; audio_track < xmv->audio_track_count; audio_track++) {
         xmv->audio[audio_track].data_offset = data_offset;
         data_offset += xmv->audio[audio_track].data_size;
     }
 
     /* Video frames header */
 
     /* Read new video extra data */
     if (xmv->video.data_size > 0) {
         if (xmv->video.has_extradata) {
             xmv_read_extradata(xmv->video.extradata, pb);
 
             xmv->video.data_size   -= 4;
             xmv->video.data_offset += 4;
 
             if (xmv->video.stream_index >= 0) {
                 AVStream *vst = s->streams[xmv->video.stream_index];
 

                 av_assert0(xmv->video.stream_index < s->nb_streams);

                 if (vst->codecpar->extradata_size < 4) {

                     av_freep(&vst->codecpar->extradata);

                     if ((ret = ff_alloc_extradata(vst->codecpar, 4)) < 0)

                         return ret;

                 }
 

                 memcpy(vst->codecpar->extradata, xmv->video.extradata, 4);

             }
         }
     }
 
     return 0;
 }
 
 static int xmv_fetch_new_packet(AVFormatContext *s)
 {
     XMVDemuxContext *xmv = s->priv_data;
     AVIOContext     *pb  = s->pb;
     int result;
 

     if (xmv->this_packet_offset == xmv->next_packet_offset)
         return AVERROR_EOF;
 

     /* Seek to it */
     xmv->this_packet_offset = xmv->next_packet_offset;
     if (avio_seek(pb, xmv->this_packet_offset, SEEK_SET) != xmv->this_packet_offset)
         return AVERROR(EIO);
 
     /* Update the size */
     xmv->this_packet_size = xmv->next_packet_size;
     if (xmv->this_packet_size < (12 + xmv->audio_track_count * 4))
         return AVERROR(EIO);
 
     /* Process the header */
     result = xmv_process_packet_header(s);
     if (result)
         return result;
 
     /* Update the offset */
     xmv->next_packet_offset = xmv->this_packet_offset + xmv->this_packet_size;
 
     return 0;
 }
 
 static int xmv_fetch_audio_packet(AVFormatContext *s,
                                   AVPacket *pkt, uint32_t stream)
 {
     XMVDemuxContext *xmv   = s->priv_data;
     AVIOContext     *pb    = s->pb;
     XMVAudioPacket  *audio = &xmv->audio[stream];
 
     uint32_t data_size;
     uint32_t block_count;
     int result;
 
     /* Seek to it */
     if (avio_seek(pb, audio->data_offset, SEEK_SET) != audio->data_offset)
         return AVERROR(EIO);
 
     if ((xmv->video.current_frame + 1) < xmv->video.frame_count)
         /* Not the last frame, get at most frame_size bytes. */
         data_size = FFMIN(audio->frame_size, audio->data_size);
     else
         /* Last frame, get the rest. */
         data_size = audio->data_size;
 
     /* Read the packet */
     result = av_get_packet(pb, pkt, data_size);
     if (result <= 0)
         return result;
 
     pkt->stream_index = audio->stream_index;
 
     /* Calculate the PTS */
 

     block_count = data_size / audio->block_align;

 
     pkt->duration = block_count;
     pkt->pts      = audio->block_count;
     pkt->dts      = AV_NOPTS_VALUE;
 
     audio->block_count += block_count;
 
     /* Advance offset */
     audio->data_size   -= data_size;
     audio->data_offset += data_size;
 
     return 0;
 }
 
 static int xmv_fetch_video_packet(AVFormatContext *s,
                                   AVPacket *pkt)
 {
     XMVDemuxContext *xmv   = s->priv_data;
     AVIOContext     *pb    = s->pb;
     XMVVideoPacket  *video = &xmv->video;
 
     int result;
     uint32_t frame_header;
     uint32_t frame_size, frame_timestamp;

     uint8_t *data, *end;

 
     /* Seek to it */
     if (avio_seek(pb, video->data_offset, SEEK_SET) != video->data_offset)
         return AVERROR(EIO);
 
     /* Read the frame header */
     frame_header = avio_rl32(pb);
 
     frame_size      = (frame_header & 0x1FFFF) * 4 + 4;
     frame_timestamp = (frame_header >> 17);
 
     if ((frame_size + 4) > video->data_size)
         return AVERROR(EIO);
 

     /* Get the packet data */
     result = av_get_packet(pb, pkt, frame_size);
     if (result != frame_size)

         return result;
 
     /* Contrary to normal WMV2 video, the bit stream in XMV's
      * WMV2 is little-endian.
      * TODO: This manual swap is of course suboptimal.
      */

     for (data = pkt->data, end = pkt->data + frame_size; data < end; data += 4)
         AV_WB32(data, AV_RL32(data));

 
     pkt->stream_index = video->stream_index;
 
     /* Calculate the PTS */
 
     video->last_pts = frame_timestamp + video->pts;
 
     pkt->duration = 0;
     pkt->pts      = video->last_pts;
     pkt->dts      = AV_NOPTS_VALUE;
 
     video->pts += frame_timestamp;
 
     /* Keyframe? */
     pkt->flags = (pkt->data[0] & 0x80) ? 0 : AV_PKT_FLAG_KEY;
 
     /* Advance offset */
     video->data_size   -= frame_size + 4;
     video->data_offset += frame_size + 4;
 
     return 0;
 }
 
 static int xmv_read_packet(AVFormatContext *s,
                            AVPacket *pkt)
 {
     XMVDemuxContext *xmv = s->priv_data;
     int result;
 
     if (xmv->video.current_frame == xmv->video.frame_count) {
         /* No frames left in this packet, so we fetch a new one */
 
         result = xmv_fetch_new_packet(s);
         if (result)
             return result;
     }
 
     if (xmv->current_stream == 0) {
         /* Fetch a video frame */
 
         result = xmv_fetch_video_packet(s, pkt);
     } else {
         /* Fetch an audio frame */
 
         result = xmv_fetch_audio_packet(s, pkt, xmv->current_stream - 1);
     }

     if (result) {
         xmv->current_stream = 0;
         xmv->video.current_frame = xmv->video.frame_count;

         return result;

     }

 
     /* Increase our counters */
     if (++xmv->current_stream >= xmv->stream_count) {
         xmv->current_stream       = 0;
         xmv->video.current_frame += 1;
     }
 
     return 0;
 }
 
 AVInputFormat ff_xmv_demuxer = {
     .name           = "xmv",
     .long_name      = NULL_IF_CONFIG_SMALL("Microsoft XMV"),

     .extensions     = "xmv",

     .priv_data_size = sizeof(XMVDemuxContext),
     .read_probe     = xmv_probe,
     .read_header    = xmv_read_header,
     .read_packet    = xmv_read_packet,
     .read_close     = xmv_read_close,
 };