From 71981d7d4d19cc0e812b55c698e15f1654106c32 Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Sat, 17 Oct 2020 19:34:15 +0200 Subject: [PATCH] avcodec/movtextdec: Use bytestream API Improves readability. Reviewed-by: Philip Langdale Signed-off-by: Andreas Rheinhardt --- libavcodec/movtextdec.c | 74 ++++++++++++++++------------------------- 1 file changed, 28 insertions(+), 46 deletions(-) diff --git a/libavcodec/movtextdec.c b/libavcodec/movtextdec.c index e5ce58a184..95dfb2a0af 100644 --- a/libavcodec/movtextdec.c +++ b/libavcodec/movtextdec.c @@ -27,6 +27,7 @@ #include "libavutil/bprint.h" #include "libavutil/intreadwrite.h" #include "libavutil/mem.h" +#include "bytestream.h" #define STYLE_FLAG_BOLD (1<<0) #define STYLE_FLAG_ITALIC (1<<1) @@ -137,7 +138,7 @@ static void mov_text_cleanup_ftab(MovTextContext *m) static int mov_text_tx3g(AVCodecContext *avctx, MovTextContext *m) { - uint8_t *tx3g_ptr = avctx->extradata; + const uint8_t *tx3g_ptr = avctx->extradata; int i, j = -1, font_length, remaining = avctx->extradata_size - BOX_SIZE_INITIAL; int8_t v_align, h_align; unsigned ftab_entries; @@ -150,8 +151,8 @@ static int mov_text_tx3g(AVCodecContext *avctx, MovTextContext *m) // Display Flags tx3g_ptr += 4; // Alignment - h_align = *tx3g_ptr++; - v_align = *tx3g_ptr++; + h_align = bytestream_get_byte(&tx3g_ptr); + v_align = bytestream_get_byte(&tx3g_ptr); if (h_align == 0) { if (v_align == 0) m->d.alignment = TOP_LEFT; @@ -177,29 +178,24 @@ static int mov_text_tx3g(AVCodecContext *avctx, MovTextContext *m) m->d.alignment = BOTTOM_RIGHT; } // Background Color - m->d.back_color = AV_RB24(tx3g_ptr); - tx3g_ptr += 3; - m->d.back_alpha = AV_RB8(tx3g_ptr); - tx3g_ptr += 1; + m->d.back_color = bytestream_get_be24(&tx3g_ptr); + m->d.back_alpha = bytestream_get_byte(&tx3g_ptr); // BoxRecord tx3g_ptr += 8; // StyleRecord tx3g_ptr += 4; // fontID - m->d.fontID = AV_RB16(tx3g_ptr); - tx3g_ptr += 2; + m->d.fontID = bytestream_get_be16(&tx3g_ptr); // face-style-flags - s_default.style_flag = *tx3g_ptr++; + s_default.style_flag = bytestream_get_byte(&tx3g_ptr); m->d.bold = !!(s_default.style_flag & STYLE_FLAG_BOLD); m->d.italic = !!(s_default.style_flag & STYLE_FLAG_ITALIC); m->d.underline = !!(s_default.style_flag & STYLE_FLAG_UNDERLINE); // fontsize - m->d.fontsize = *tx3g_ptr++; + m->d.fontsize = bytestream_get_byte(&tx3g_ptr); // Primary color - m->d.color = AV_RB24(tx3g_ptr); - tx3g_ptr += 3; - m->d.alpha = AV_RB8(tx3g_ptr); - tx3g_ptr += 1; + m->d.color = bytestream_get_be24(&tx3g_ptr); + m->d.alpha = bytestream_get_byte(&tx3g_ptr); // FontRecord // FontRecord Size tx3g_ptr += 4; @@ -209,7 +205,7 @@ static int mov_text_tx3g(AVCodecContext *avctx, MovTextContext *m) // In case of broken header, init default font m->d.font = ASS_DEFAULT_FONT; - ftab_entries = AV_RB16(tx3g_ptr); + ftab_entries = bytestream_get_be16(&tx3g_ptr); if (!ftab_entries) return 0; remaining -= 3 * ftab_entries; @@ -219,14 +215,12 @@ static int mov_text_tx3g(AVCodecContext *avctx, MovTextContext *m) if (!m->ftab) return AVERROR(ENOMEM); m->ftab_entries = ftab_entries; - tx3g_ptr += 2; for (i = 0; i < m->ftab_entries; i++) { - m->ftab[i].fontID = AV_RB16(tx3g_ptr); + m->ftab[i].fontID = bytestream_get_be16(&tx3g_ptr); if (m->ftab[i].fontID == m->d.fontID) j = i; - tx3g_ptr += 2; - font_length = *tx3g_ptr++; + font_length = bytestream_get_byte(&tx3g_ptr); remaining -= font_length; if (remaining < 0) { @@ -238,9 +232,8 @@ static int mov_text_tx3g(AVCodecContext *avctx, MovTextContext *m) mov_text_cleanup_ftab(m); return AVERROR(ENOMEM); } - memcpy(m->ftab[i].font, tx3g_ptr, font_length); + bytestream_get_buffer(&tx3g_ptr, m->ftab[i].font, font_length); m->ftab[i].font[font_length] = '\0'; - tx3g_ptr = tx3g_ptr + font_length; } if (j >= 0) m->d.font = m->ftab[j].font; @@ -250,34 +243,31 @@ static int mov_text_tx3g(AVCodecContext *avctx, MovTextContext *m) static int decode_twrp(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) { m->box_flags |= TWRP_BOX; - m->w.wrap_flag = *tsmb++; + m->w.wrap_flag = bytestream_get_byte(&tsmb); return 0; } static int decode_hlit(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) { m->box_flags |= HLIT_BOX; - m->h.hlit_start = AV_RB16(tsmb); - tsmb += 2; - m->h.hlit_end = AV_RB16(tsmb); - tsmb += 2; + m->h.hlit_start = bytestream_get_be16(&tsmb); + m->h.hlit_end = bytestream_get_be16(&tsmb); return 0; } static int decode_hclr(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) { m->box_flags |= HCLR_BOX; - memcpy(m->c.hlit_color, tsmb, 4); - tsmb += 4; + bytestream_get_buffer(&tsmb, m->c.hlit_color, 4); return 0; } static int decode_styl(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) { int i; - int style_entries = AV_RB16(tsmb); + int style_entries = bytestream_get_be16(&tsmb); StyleBox *tmp; - tsmb += 2; + // A single style record is of length 12 bytes. if (m->tracksize + m->size_var + 2 + style_entries * 12 > avpkt->size) return -1; @@ -291,17 +281,14 @@ static int decode_styl(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) m->box_flags |= STYL_BOX; for(i = 0; i < m->style_entries; i++) { StyleBox *style = &m->s[i]; - style->style_start = AV_RB16(tsmb); - tsmb += 2; - style->style_end = AV_RB16(tsmb); + style->style_start = bytestream_get_be16(&tsmb); + style->style_end = bytestream_get_be16(&tsmb); if ( style->style_end < style->style_start || (i && style->style_start < m->s[i - 1].style_end)) { mov_text_cleanup(m); return AVERROR(ENOMEM); } - - tsmb += 2; if (style->style_start == style->style_end) { /* Skip this style as it applies to no character */ tsmb += 8; @@ -310,19 +297,14 @@ static int decode_styl(const uint8_t *tsmb, MovTextContext *m, AVPacket *avpkt) continue; } - style->style_fontID = AV_RB16(tsmb); - tsmb += 2; - style->style_flag = AV_RB8(tsmb); + style->style_fontID = bytestream_get_be16(&tsmb); + style->style_flag = bytestream_get_byte(&tsmb); style->bold = !!(style->style_flag & STYLE_FLAG_BOLD); style->italic = !!(style->style_flag & STYLE_FLAG_ITALIC); style->underline = !!(style->style_flag & STYLE_FLAG_UNDERLINE); - tsmb++; - style->fontsize = AV_RB8(tsmb); - tsmb++; - style->color = AV_RB24(tsmb); - tsmb += 3; - style->alpha = AV_RB8(tsmb); - tsmb++; + style->fontsize = bytestream_get_byte(&tsmb); + style->color = bytestream_get_be24(&tsmb); + style->alpha = bytestream_get_byte(&tsmb); } return 0; }