/* *  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 <stdio.h>#include <stdlib.h>#include <string.h> #include "vpx_ports/mem_ops.h" #include "./ivfdec.h" static const char *IVF_SIGNATURE = "DKIF"; static void fix_framerate(int *num, int *den) {  // Some versions of vpxenc used 1/(2*fps) for the timebase, so  // we can guess the framerate using only the timebase in this  // case. Other files would require reading ahead to guess the  // timebase, like we do for webm.  if (*den > 0 && *den < 1000000000 && *num > 0 && *num < 1000) {    // Correct for the factor of 2 applied to the timebase in the encoder.    if (*num & 1)      *den *= 2;    else      *num /= 2;  } else {    // Don't know FPS for sure, and don't have readahead code    // (yet?), so just default to 30fps.    *num = 30;    *den = 1;  }} int file_is_ivf(struct VpxInputContext *input_ctx) {  char raw_hdr[32];  int is_ivf = 0;   if (fread(raw_hdr, 1, 32, input_ctx->file) == 32) {    if (memcmp(IVF_SIGNATURE, raw_hdr, 4) == 0) {      is_ivf = 1;       if (mem_get_le16(raw_hdr + 4) != 0) {        fprintf(stderr,                "Error: Unrecognized IVF version! This file may not"                " decode properly.");      }       input_ctx->fourcc = mem_get_le32(raw_hdr + 8);      input_ctx->width = mem_get_le16(raw_hdr + 12);      input_ctx->height = mem_get_le16(raw_hdr + 14);      input_ctx->framerate.numerator = mem_get_le32(raw_hdr + 16);      input_ctx->framerate.denominator = mem_get_le32(raw_hdr + 20);      fix_framerate(&input_ctx->framerate.numerator,                    &input_ctx->framerate.denominator);    }  }   if (!is_ivf) {    rewind(input_ctx->file);    input_ctx->detect.buf_read = 0;  } else {    input_ctx->detect.position = 4;  }  return is_ivf;} int ivf_read_frame(FILE *infile, uint8_t **buffer, size_t *bytes_read,                   size_t *buffer_size) {  char raw_header[IVF_FRAME_HDR_SZ] = { 0 };  size_t frame_size = 0;   if (fread(raw_header, IVF_FRAME_HDR_SZ, 1, infile) != 1) {    if (!feof(infile)) warn("Failed to read frame size");  } else {    frame_size = mem_get_le32(raw_header);     if (frame_size > 256 * 1024 * 1024) {      warn("Read invalid frame size (%u)", (unsigned int)frame_size);      frame_size = 0;    }     if (frame_size > *buffer_size) {      uint8_t *new_buffer = realloc(*buffer, 2 * frame_size);       if (new_buffer) {        *buffer = new_buffer;        *buffer_size = 2 * frame_size;      } else {        warn("Failed to allocate compressed data buffer");        frame_size = 0;      }    }  }   if (!feof(infile)) {    if (fread(*buffer, 1, frame_size, infile) != frame_size) {      warn("Failed to read full frame");      return 1;    }     *bytes_read = frame_size;    return 0;  }   return 1;}