static int vcr1_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; VCR1Context *const a = avctx->priv_data; AVFrame *const p = data; const uint8_t *bytestream = buf; int i, x, y, ret; if ((ret = ff_get_buffer(avctx, p, 0)) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return ret; } p->pict_type = AV_PICTURE_TYPE_I; p->key_frame = 1; if (buf_size < 32) goto packet_small; for (i = 0; i < 16; i++) { a->delta[i] = *bytestream++; bytestream++; buf_size--; } for (y = 0; y < avctx->height; y++) { int offset; uint8_t *luma = &p->data[0][y * p->linesize[0]]; if ((y & 3) == 0) { uint8_t *cb = &p->data[1][(y >> 2) * p->linesize[1]]; uint8_t *cr = &p->data[2][(y >> 2) * p->linesize[2]]; if (buf_size < 4 + avctx->width) goto packet_small; for (i = 0; i < 4; i++) a->offset[i] = *bytestream++; buf_size -= 4; offset = a->offset[0] - a->delta[bytestream[2] & 0xF]; for (x = 0; x < avctx->width; x += 4) { luma[0] = offset += a->delta[bytestream[2] & 0xF]; luma[1] = offset += a->delta[bytestream[2] >> 4]; luma[2] = offset += a->delta[bytestream[0] & 0xF]; luma[3] = offset += a->delta[bytestream[0] >> 4]; luma += 4; *cb++ = bytestream[3]; *cr++ = bytestream[1]; bytestream += 4; } } else { if (buf_size < avctx->width / 2) goto packet_small; offset = a->offset[y & 3] - a->delta[bytestream[2] & 0xF]; for (x = 0; x < avctx->width; x += 8) { luma[0] = offset += a->delta[bytestream[2] & 0xF]; luma[1] = offset += a->delta[bytestream[2] >> 4]; luma[2] = offset += a->delta[bytestream[3] & 0xF]; luma[3] = offset += a->delta[bytestream[3] >> 4]; luma[4] = offset += a->delta[bytestream[0] & 0xF]; luma[5] = offset += a->delta[bytestream[0] >> 4]; luma[6] = offset += a->delta[bytestream[1] & 0xF]; luma[7] = offset += a->delta[bytestream[1] >> 4]; luma += 8; bytestream += 4; } } } *got_frame = 1; return buf_size; packet_small: av_log(avctx, AV_LOG_ERROR, "Input packet too small.\n"); return AVERROR_INVALIDDATA; }
static int vcr1_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt) { const uint8_t *buf = avpkt->data; int buf_size = avpkt->size; VCR1Context *const a = avctx->priv_data; AVFrame *const p = data; const uint8_t *bytestream = buf; int i, x, y, ret; if ((ret = ff_get_buffer(avctx, p, 0)) < 0) { av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); return ret; } p->pict_type = AV_PICTURE_TYPE_I; p->key_frame = 1; if (buf_size < 32) goto packet_small; for (i = 0; i < 16; i++) { a->delta[i] = *bytestream++; bytestream++; buf_size--; } for (y = 0; y < avctx->height; y++) { int offset; uint8_t *luma = &p->data[0][y * p->linesize[0]]; if ((y & 3) == 0) { uint8_t *cb = &p->data[1][(y >> 2) * p->linesize[1]]; uint8_t *cr = &p->data[2][(y >> 2) * p->linesize[2]]; if (buf_size < 4 + avctx->width) goto packet_small; for (i = 0; i < 4; i++) a->offset[i] = *bytestream++; buf_size -= 4; offset = a->offset[0] - a->delta[bytestream[2] & 0xF]; for (x = 0; x < avctx->width; x += 4) { luma[0] = offset += a->delta[bytestream[2] & 0xF]; luma[1] = offset += a->delta[bytestream[2] >> 4]; luma[2] = offset += a->delta[bytestream[0] & 0xF]; luma[3] = offset += a->delta[bytestream[0] >> 4]; luma += 4; *cb++ = bytestream[3]; *cr++ = bytestream[1]; bytestream += 4; } } else { if (buf_size < avctx->width / 2) goto packet_small; offset = a->offset[y & 3] - a->delta[bytestream[2] & 0xF]; for (x = 0; x < avctx->width; x += 8) { luma[0] = offset += a->delta[bytestream[2] & 0xF]; luma[1] = offset += a->delta[bytestream[2] >> 4]; luma[2] = offset += a->delta[bytestream[3] & 0xF]; luma[3] = offset += a->delta[bytestream[3] >> 4]; luma[4] = offset += a->delta[bytestream[0] & 0xF]; luma[5] = offset += a->delta[bytestream[0] >> 4]; luma[6] = offset += a->delta[bytestream[1] & 0xF]; luma[7] = offset += a->delta[bytestream[1] >> 4]; luma += 8; bytestream += 4; } } } *got_frame = 1; return buf_size; packet_small: av_log(avctx, AV_LOG_ERROR, "Input packet too small.\n"); return AVERROR_INVALIDDATA; }