• Stefan Holmer's avatar
    Adding error-concealment to the decoder. · d04f8523
    Stefan Holmer authored
    The error-concealer is plugged in after any motion vectors have been
    decoded. It tries to estimate any missing motion vectors from the
    motion vectors of the previous frame. Intra blocks with missing
    residual are replaced with inter blocks with estimated motion vectors.
    
    This feature was developed in a separate sandbox
    (sandbox/holmer/error-concealment).
    
    Change-Id: I5c8917b031078d79dbafd90f6006680e84a23412
    d04f8523
webmenc.c 10.20 KiB
/*
 *  Copyright (c) 2013 The WebM project authors. All Rights Reserved.
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
#include "webmenc.h"
#include <limits.h>
#include <string.h>
#include "third_party/libmkv/EbmlWriter.h"
#include "third_party/libmkv/EbmlIDs.h"
void Ebml_Write(struct EbmlGlobal *glob,
                const void *buffer_in,
                unsigned long len) {
  (void) fwrite(buffer_in, 1, len, glob->stream);
#define WRITE_BUFFER(s) \
for (i = len - 1; i >= 0; i--) { \
  x = (char)(*(const s *)buffer_in >> (i * CHAR_BIT)); \
  Ebml_Write(glob, &x, 1); \
void Ebml_Serialize(struct EbmlGlobal *glob,
                    const void *buffer_in,
                    int buffer_size,
                    unsigned long len) {
  char x;
  int i;
  /* buffer_size:
   * 1 - int8_t;
   * 2 - int16_t;
   * 3 - int32_t;
   * 4 - int64_t;
  switch (buffer_size) {
    case 1:
      WRITE_BUFFER(int8_t)
      break;
    case 2:
      WRITE_BUFFER(int16_t)
      break;
    case 4:
      WRITE_BUFFER(int32_t)
      break;
    case 8:
      WRITE_BUFFER(int64_t)
      break;
    default:
      break;
#undef WRITE_BUFFER
/* Need a fixed size serializer for the track ID. libmkv provides a 64 bit
 * one, but not a 32 bit one.
static void Ebml_SerializeUnsigned32(struct EbmlGlobal *glob,
                                     unsigned int class_id,
                                     uint64_t ui) {
  const unsigned char sizeSerialized = 4 | 0x80;
  Ebml_WriteID(glob, class_id);
  Ebml_Serialize(glob, &sizeSerialized, sizeof(sizeSerialized), 1);
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Ebml_Serialize(glob, &ui, sizeof(ui), 4); } static void Ebml_StartSubElement(struct EbmlGlobal *glob, EbmlLoc *ebmlLoc, unsigned int class_id) { const uint64_t kEbmlUnknownLength = LITERALU64(0x01FFFFFF, 0xFFFFFFFF); Ebml_WriteID(glob, class_id); *ebmlLoc = ftello(glob->stream); Ebml_Serialize(glob, &kEbmlUnknownLength, sizeof(kEbmlUnknownLength), 8); } static void Ebml_EndSubElement(struct EbmlGlobal *glob, EbmlLoc *ebmlLoc) { off_t pos; uint64_t size; /* Save the current stream pointer. */ pos = ftello(glob->stream); /* Calculate the size of this element. */ size = pos - *ebmlLoc - 8; size |= LITERALU64(0x01000000, 0x00000000); /* Seek back to the beginning of the element and write the new size. */ fseeko(glob->stream, *ebmlLoc, SEEK_SET); Ebml_Serialize(glob, &size, sizeof(size), 8); /* Reset the stream pointer. */ fseeko(glob->stream, pos, SEEK_SET); } void write_webm_seek_element(struct EbmlGlobal *ebml, unsigned int id, off_t pos) { uint64_t offset = pos - ebml->position_reference; EbmlLoc start; Ebml_StartSubElement(ebml, &start, Seek); Ebml_SerializeBinary(ebml, SeekID, id); Ebml_SerializeUnsigned64(ebml, SeekPosition, offset); Ebml_EndSubElement(ebml, &start); } void write_webm_seek_info(struct EbmlGlobal *ebml) { off_t pos; EbmlLoc start; EbmlLoc startInfo; uint64_t frame_time; char version_string[64]; /* Save the current stream pointer. */ pos = ftello(ebml->stream); if (ebml->seek_info_pos) fseeko(ebml->stream, ebml->seek_info_pos, SEEK_SET); else ebml->seek_info_pos = pos; Ebml_StartSubElement(ebml, &start, SeekHead); write_webm_seek_element(ebml, Tracks, ebml->track_pos); write_webm_seek_element(ebml, Cues, ebml->cue_pos); write_webm_seek_element(ebml, Info, ebml->segment_info_pos); Ebml_EndSubElement(ebml, &start); /* Create and write the Segment Info. */ if (ebml->debug) { strcpy(version_string, "vpxenc"); } else { strcpy(version_string, "vpxenc "); strncat(version_string, vpx_codec_version_str(),
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sizeof(version_string) - 1 - strlen(version_string)); } frame_time = (uint64_t)1000 * ebml->framerate.den / ebml->framerate.num; ebml->segment_info_pos = ftello(ebml->stream); Ebml_StartSubElement(ebml, &startInfo, Info); Ebml_SerializeUnsigned(ebml, TimecodeScale, 1000000); Ebml_SerializeFloat(ebml, Segment_Duration, (double)(ebml->last_pts_ms + frame_time)); Ebml_SerializeString(ebml, 0x4D80, version_string); Ebml_SerializeString(ebml, 0x5741, version_string); Ebml_EndSubElement(ebml, &startInfo); } void write_webm_file_header(struct EbmlGlobal *glob, const vpx_codec_enc_cfg_t *cfg, const struct vpx_rational *fps, stereo_format_t stereo_fmt, unsigned int fourcc) { EbmlLoc start; EbmlLoc trackStart; EbmlLoc videoStart; unsigned int trackNumber = 1; uint64_t trackID = 0; unsigned int pixelWidth = cfg->g_w; unsigned int pixelHeight = cfg->g_h; /* Write the EBML header. */ Ebml_StartSubElement(glob, &start, EBML); Ebml_SerializeUnsigned(glob, EBMLVersion, 1); Ebml_SerializeUnsigned(glob, EBMLReadVersion, 1); Ebml_SerializeUnsigned(glob, EBMLMaxIDLength, 4); Ebml_SerializeUnsigned(glob, EBMLMaxSizeLength, 8); Ebml_SerializeString(glob, DocType, "webm"); Ebml_SerializeUnsigned(glob, DocTypeVersion, 2); Ebml_SerializeUnsigned(glob, DocTypeReadVersion, 2); Ebml_EndSubElement(glob, &start); /* Open and begin writing the segment element. */ Ebml_StartSubElement(glob, &glob->startSegment, Segment); glob->position_reference = ftello(glob->stream); glob->framerate = *fps; write_webm_seek_info(glob); /* Open and write the Tracks element. */ glob->track_pos = ftello(glob->stream); Ebml_StartSubElement(glob, &trackStart, Tracks); /* Open and write the Track entry. */ Ebml_StartSubElement(glob, &start, TrackEntry); Ebml_SerializeUnsigned(glob, TrackNumber, trackNumber); glob->track_id_pos = ftello(glob->stream); Ebml_SerializeUnsigned32(glob, TrackUID, trackID); Ebml_SerializeUnsigned(glob, TrackType, 1); Ebml_SerializeString(glob, CodecID, fourcc == VP8_FOURCC ? "V_VP8" : "V_VP9"); Ebml_StartSubElement(glob, &videoStart, Video); Ebml_SerializeUnsigned(glob, PixelWidth, pixelWidth); Ebml_SerializeUnsigned(glob, PixelHeight, pixelHeight); Ebml_SerializeUnsigned(glob, StereoMode, stereo_fmt); Ebml_EndSubElement(glob, &videoStart); /* Close Track entry. */ Ebml_EndSubElement(glob, &start); /* Close Tracks element. */ Ebml_EndSubElement(glob, &trackStart); /* Segment element remains open. */
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} void write_webm_block(struct EbmlGlobal *glob, const vpx_codec_enc_cfg_t *cfg, const vpx_codec_cx_pkt_t *pkt) { unsigned int block_length; unsigned char track_number; uint16_t block_timecode = 0; unsigned char flags; int64_t pts_ms; int start_cluster = 0, is_keyframe; /* Calculate the PTS of this frame in milliseconds. */ pts_ms = pkt->data.frame.pts * 1000 * (uint64_t)cfg->g_timebase.num / (uint64_t)cfg->g_timebase.den; if (pts_ms <= glob->last_pts_ms) pts_ms = glob->last_pts_ms + 1; glob->last_pts_ms = pts_ms; /* Calculate the relative time of this block. */ if (pts_ms - glob->cluster_timecode > SHRT_MAX) start_cluster = 1; else block_timecode = (uint16_t)pts_ms - glob->cluster_timecode; is_keyframe = (pkt->data.frame.flags & VPX_FRAME_IS_KEY); if (start_cluster || is_keyframe) { if (glob->cluster_open) Ebml_EndSubElement(glob, &glob->startCluster); /* Open the new cluster. */ block_timecode = 0; glob->cluster_open = 1; glob->cluster_timecode = (uint32_t)pts_ms; glob->cluster_pos = ftello(glob->stream); Ebml_StartSubElement(glob, &glob->startCluster, Cluster); Ebml_SerializeUnsigned(glob, Timecode, glob->cluster_timecode); /* Save a cue point if this is a keyframe. */ if (is_keyframe) { struct cue_entry *cue, *new_cue_list; new_cue_list = realloc(glob->cue_list, (glob->cues + 1) * sizeof(struct cue_entry)); if (new_cue_list) glob->cue_list = new_cue_list; else fatal("Failed to realloc cue list."); cue = &glob->cue_list[glob->cues]; cue->time = glob->cluster_timecode; cue->loc = glob->cluster_pos; glob->cues++; } } /* Write the Simple Block. */ Ebml_WriteID(glob, SimpleBlock); block_length = (unsigned int)pkt->data.frame.sz + 4; block_length |= 0x10000000; Ebml_Serialize(glob, &block_length, sizeof(block_length), 4); track_number = 1; track_number |= 0x80; Ebml_Write(glob, &track_number, 1); Ebml_Serialize(glob, &block_timecode, sizeof(block_timecode), 2);
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flags = 0; if (is_keyframe) flags |= 0x80; if (pkt->data.frame.flags & VPX_FRAME_IS_INVISIBLE) flags |= 0x08; Ebml_Write(glob, &flags, 1); Ebml_Write(glob, pkt->data.frame.buf, (unsigned int)pkt->data.frame.sz); } void write_webm_file_footer(struct EbmlGlobal *glob, int hash) { EbmlLoc start_cues; EbmlLoc start_cue_point; EbmlLoc start_cue_tracks; unsigned int i; if (glob->cluster_open) Ebml_EndSubElement(glob, &glob->startCluster); glob->cue_pos = ftello(glob->stream); Ebml_StartSubElement(glob, &start_cues, Cues); for (i = 0; i < glob->cues; i++) { struct cue_entry *cue = &glob->cue_list[i]; Ebml_StartSubElement(glob, &start_cue_point, CuePoint); Ebml_SerializeUnsigned(glob, CueTime, cue->time); Ebml_StartSubElement(glob, &start_cue_tracks, CueTrackPositions); Ebml_SerializeUnsigned(glob, CueTrack, 1); Ebml_SerializeUnsigned64(glob, CueClusterPosition, cue->loc - glob->position_reference); Ebml_EndSubElement(glob, &start_cue_tracks); Ebml_EndSubElement(glob, &start_cue_point); } Ebml_EndSubElement(glob, &start_cues); /* Close the Segment. */ Ebml_EndSubElement(glob, &glob->startSegment); /* Patch up the seek info block. */ write_webm_seek_info(glob); /* Patch up the track id. */ fseeko(glob->stream, glob->track_id_pos, SEEK_SET); Ebml_SerializeUnsigned32(glob, TrackUID, glob->debug ? 0xDEADBEEF : hash); fseeko(glob->stream, 0, SEEK_END); }